RESUMEN
BACKGROUND: Systemic right ventricular systolic dysfunction is common late after atrial switch surgery for transposition of the great arteries. Total isovolumic time is the time that the ventricle is neither ejecting nor filling and is calculated without relying on geometric assumptions. We assessed resting total isovolumic time in this population and its relationship to exercise capacity. METHODS: A total of 40 adult patients with transposition of the great arteries after atrial switch - and 10 healthy controls - underwent transthoracic echocardiography and cardiopulmonary exercise testing from January, 2006 to January, 2009. Resting total isovolumic time was measured in seconds per minute: 60 minus total ejection time plus total filling time. RESULTS: The mean age was 31.6 plus or minus 7.6 years, and 38.0% were men. There were 16 patients (40%) who had more than or equal to moderate systolic dysfunction of the right ventricle. Intra- and inter-observer agreement was good for total isovolumic time, which was significantly prolonged in patients compared with controls (12.0 plus or minus 3.9 seconds per minute versus 6.0 plus or minus 1.8 seconds per minute, p-value less than 0.001) and correlated significantly with peak oxygen consumption (r equals minus 0.63, p-value less than 0.001). The correlation strengthened (r equals minus 0.73, p-value less than 0.001) after excluding seven patients with exercise-induced cyanosis. No relationship was found between exercise capacity and right ventricular ejection fraction or long-axis amplitude. CONCLUSION: Resting isovolumic time is prolonged after atrial switch for patients with transposition of the great arteries. It is highly reproducible and relates well to exercise capacity.
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Tolerancia al Ejercicio , Corazón/fisiopatología , Transposición de los Grandes Vasos/fisiopatología , Adulto , Procedimientos Quirúrgicos Cardíacos , Estudios de Casos y Controles , Ecocardiografía , Prueba de Esfuerzo , Femenino , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Consumo de Oxígeno , Factores de Tiempo , Transposición de los Grandes Vasos/cirugía , Función Ventricular DerechaRESUMEN
BACKGROUND: Patients after repair of tetralogy of Fallot (ToF) frequently have right ventricular (RV) dysfunction and prolonged QRS duration (QRSd) and thus could be candidates for cardiac resynchronization therapy. We aimed to assess the relationship between QRSd and the timing of RV wall motion, including the RV outflow tract (RVOT), in these patients. METHODS AND RESULTS: Sixty-seven repaired ToF patients (median age, 34 years; interquartile range, 24 to 43 years) and 35 age-matched control subjects were studied by echocardiography and cardiovascular magnetic resonance (n=55 of 67 ToF patients). Time intervals of the RV cardiac cycle were measured from Doppler recordings. Long-axis M-mode recordings were acquired from the right ventricular (RV) free wall and RV outflow tract (RVOT), and the delay in onset of long-axis shortening was measured. ToF patients showed minor abnormalities of the RV cardiac cycle unrelated to QRSd. RV ejection time was prolonged and correspondingly filling time was reduced compared with control subjects (22.3+/-2.6 versus 20.0+/-2.9 s/min, P<0.0001; 29.0+/-3.8 versus 32.7+/-3.5 s/min, P<0.0001). Total isovolumic time was normal in ToF patients (8.7+/-4.0 versus 7.4+/-2.9 s/min; P=NS). QRSd correlated with the delay in RV free wall motion (r=0.55, P<0.0001) and more so with the delay in RVOT shortening (r=0.82, P<0.0001). QRSd also correlated with measures of RVOT abnormality such as long-axis RVOT excursion and akinetic area length (r=-0.46, P=0.004; r=0.33, P=0.01). CONCLUSIONS: QRSd in postoperative ToF patients reflects mainly abnormalities of the RVOT rather than the RV body itself. Thus, prevention and treatment of mechanical asynchrony and malignant arrhythmia should focus on the RV infundibulum. Indications for cardiac resynchronization therapy after ToF repair warrant further investigation.
Asunto(s)
Bloqueo de Rama/diagnóstico , Bloqueo de Rama/fisiopatología , Electrocardiografía , Tetralogía de Fallot/fisiopatología , Función Ventricular Derecha/fisiología , Adulto , Bloqueo de Rama/terapia , Estimulación Cardíaca Artificial , Ecocardiografía/normas , Sistema de Conducción Cardíaco/fisiopatología , Sistema de Conducción Cardíaco/cirugía , Humanos , Imagen por Resonancia Magnética/normas , Contracción Miocárdica , Estudios Prospectivos , Reproducibilidad de los Resultados , Tetralogía de Fallot/diagnóstico por imagen , Tetralogía de Fallot/cirugíaRESUMEN
BACKGROUND: We aimed to define differences between systemic right ventricle (RV) in patients with atrial switch procedure for transposition of the great arteries, and congenitally corrected transposition of the great arteries (ccTGA), which remodels early on in life and the subpulmonary RV in patients with idiopathic pulmonary arterial hypertension (iPAH) which remodels later in adulthood to the effects of progressive pulmonary hypertension. METHODS: Prospective echocardiographic assessment of consecutive patients with atrial switch procedure, ccTGA, and iPAH attending adult congenital heart program. Right ventricular long axis function by M-mode and tissue Doppler imaging; myocardial performance index; and total isovolumic time (t-IVT), ventricular filling time, and ejection time (ET) were studied and compared with normal left ventricle and RV. RESULTS: Seventy-eight patients (20 atrial switch, 18 ccTGA, 20 iPAH, and 20 normal) were studied. Right ventricular long axis function was most reduced after atrial switch procedure. Diastolic filling and dysfunction varied across the groups, with atrial switch patients having the lowest myocardial early diastolic (Em) and atrial diastolic (Am) velocities and iPAH patients with the longest t-IVT, shortest filling time and ET, and lowest Em/Am, reflecting predominantly late diastolic filling. Patients with ccTGA had better preserved global systemic RV systolic and diastolic indices. CONCLUSION: The RV develops adaptative mechanisms when faced with increased afterload, behaving more like normal left ventricle. This adaptation is closer when present from birth (ccTGA) without facing subsequent surgical insults. In iPAH, the RV adapts poorly, showing prolonged t-IVT and shortened filling and effective ETs, eventually resulting in lower stroke volume and overall poorer prognosis.
Asunto(s)
Hipertensión Pulmonar/fisiopatología , Transposición de los Grandes Vasos/fisiopatología , Transposición de los Grandes Vasos/cirugía , Función Ventricular , Adulto , Femenino , Humanos , Masculino , Estudios ProspectivosRESUMEN
OBJECTIVES: The purpose of this research was to study the effect of dobutamine on left ventricular (LV) filling in ischemic cardiomyopathy (ICM) and to determine whether restrictive filling pattern (RFP) at peak stress has prognostic value. BACKGROUND: The prognostic value of RFP at peak stress in ICM is unknown. METHODS: A total of 69 patients with ICM were studied by Doppler echocardiography at rest and stress; RFP was defined as transmitral E:A ratio > or =1.0, isovolumic relaxation time (IVRT) <80 ms, and E-wave deceleration time (EDT) <120 ms. RESULTS: A total of 42 of 69 had RFP at rest, which reverted to non-RFP at stress in 24 (EA), but persisted in 18 (EE); 27 of 69 had non-RFP at rest and peak stress (AA). In EA, IVRT and EDT lengthened (by 43 ms and 46 ms), and tricuspid regurgitation (TR) decreased (by 26 mm Hg, p < 0.01), suggesting a fall in left atrial (LA) pressure. The stress response in AA was similar to EA. In EE, IVRT and EDT shortened (by 21 ms) and TR increased (by 13 mm Hg, p < 0.01), suggesting a rise in LA pressure. Peak aortic acceleration (LV inotropy) increased by 0.8 g in EA but only by 0.2 g in EE (difference p < 0.001). Median follow-up (interquartile range) was 34 (20 to 57) months. Three-year survival for EE, EA, and AA was 49%, 79%, and 89%, respectively (p < 0.001). Compared with AA, the hazard ratio for EE was 9.5 (p < 0.001) and for EA was 1.9 (p = 0.30). CONCLUSIONS: In ischemic cardiomyopathy, persistence of restrictive filling during stress implies a striking rise in LA pressure, greatly attenuated LV inotropic response, and markedly reduced survival. Stress echocardiography uniquely identifies these high-risk patients.
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Cardiomiopatía Dilatada/diagnóstico por imagen , Ecocardiografía de Estrés , Volumen Sistólico , Disfunción Ventricular Izquierda/cirugía , Anciano , Cardiomiopatía Dilatada/fisiopatología , Estudios de Cohortes , Intervalos de Confianza , Femenino , Estudios de Seguimiento , Pruebas de Función Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reproducibilidad de los Resultados , Medición de Riesgo , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
BACKGROUND: Resting regional wall-motion abnormalities do not reliably distinguish ischemic from nonischemic cardiomyopathy. Dobutamine stress echocardiography with use of the wall-motion score index (WMSI) identifies coronary artery disease (CAD) in dilated cardiomyopathy (DCM), but the technique is subjective and further complicated by left bundle-branch block (LBBB). Long-axis motion is sensitive to ischemia and can be assessed quantitatively. We aimed to compare long-axis function with WMSI for detecting CAD in DCM with or without LBBB. METHODS AND RESULTS: Seventy-three patients with DCM, 48 with CAD (16 with LBBB), and 25 without CAD (10 with LBBB) were studied. Long-axis M-mode, pulsed-wave tissue Doppler echograms (lateral, septal, and posterior walls), and WMSI were assessed at rest and at peak dobutamine stress. Failure to increase systolic amplitude (total amplitude minus postejection shortening) by 2 mm or early diastolic velocity by 1.1 cm/s was the best discriminator for CAD (systolic amplitude, sensitivity 85%, specificity 86%; lengthening velocity, 71% and 94%, respectively; P=NS). Both had greater predictive accuracy than did WMSI (sensitivity 67%, specificity 76%; P<0.001). The predictive accuracy of changes in septal long-axis function was similar to those of average long-axis function (systolic amplitude cutoff=1.5 mm, lengthening velocity cutoff=1.5 cm/s). However in LBBB, systolic amplitude proved to be the only significant discriminator for CAD, with sensitivity and specificity reaching 94% and 100%, respectively (P<0.01 versus early diastolic lengthening velocity). CONCLUSIONS: Quantified stress long-axis function identifies CAD in DCM with greater sensitivity and specificity than does standard WMSI, particularly in the presence of LBBB.
Asunto(s)
Bloqueo de Rama/fisiopatología , Cardiomiopatías/diagnóstico , Dobutamina , Isquemia Miocárdica/diagnóstico , Disfunción Ventricular Izquierda/diagnóstico , Bloqueo de Rama/complicaciones , Cardiomiopatías/complicaciones , Cardiomiopatías/fisiopatología , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/fisiopatología , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Disfunción Ventricular Izquierda/etiología , Función Ventricular Izquierda/efectos de los fármacosRESUMEN
OBJECTIVES: The aim of this study was to identify resting measurements of left ventricular (LV) function that predict exercise capacity in dilated cardiomyopathy (DCM); in particular, the effects of left bundle branch block (LBBB), coronary artery disease (CAD), and total isovolumic time (t-IVT). BACKGROUND: The t-IVT is a major determinant of cardiac output during dobutamine stress in DCM, and is itself determined by the presence or absence of LBBB and CAD. METHODS: A total of 111 patients with DCM, 51 with CAD (29 LBBB), and 60 without CAD (30 LBBB) were studied with echocardiography and cardiopulmonary exercise testing. The t-IVT (in s/min) was measured by Doppler echocardiography, and maximal oxygen consumption (peak Vo(2)) and percentage of the normal predicted peak Vo(2) (%predicted peak Vo(2)) were obtained from exercise testing. RESULTS: Left bundle branch block reduced peak Vo(2) (by 10.5 ml.kg(-1)min(-1)) and %predicted peak Vo(2) (by 33%, both p < 0.001) compared with patients without LBBB. Coronary artery disease reduced peak Vo(2) (by 5.5 ml.kg(-1)min(-1), p < 0.001) and %predicted peak Vo(2) (by 14%, p < 0.01) compared with those without CAD (p < 0.01). The t-IVT, CAD, LBBB, and QRS duration were univariate predictors of exercise tolerance, but only t-IVT and CAD were independent predictors. The t-IVT at rest correlated with peak Vo(2) (r = -0.68) and %predicted peak Vo(2) (r = -0.74, both p < 0.001). The combination of t-IVT and CAD explained 57% (r = 0.75, p < 0.001) of the total variance in exercise capacity. CONCLUSIONS: Resting t-IVT and less prominently, CAD, are major determinants of exercise tolerance in DCM. Left bundle branch block significantly determines resting t-IVT and thus peak Vo(2). Prediction of maximum exercise capacity in DCM is therefore possible from time-domain analysis of LV function at rest.
Asunto(s)
Tolerancia al Ejercicio/fisiología , Insuficiencia Cardíaca/fisiopatología , Antagonistas Adrenérgicos beta/uso terapéutico , Adulto , Anciano , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Velocidad del Flujo Sanguíneo/fisiología , Bloqueo de Rama/diagnóstico , Bloqueo de Rama/tratamiento farmacológico , Bloqueo de Rama/fisiopatología , Enfermedad Crónica , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Enfermedad de la Arteria Coronaria/fisiopatología , Ecocardiografía , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/tratamiento farmacológico , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Londres , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/efectos de los fármacos , Consumo de Oxígeno/fisiología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Estadística como Asunto , Volumen Sistólico/efectos de los fármacos , Volumen Sistólico/fisiología , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/tratamiento farmacológico , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
OBJECTIVES: We sought to separate the effects of associated left bundle branch block (LBBB) and coronary artery disease (CAD) on peak cardiac output (CO) during dobutamine stress in patients with dilated cardiomyopathy (DCM). BACKGROUND: The mechanisms limiting CO during stress in patients with DCM are unclear. Both LBBB and CAD may do so by prolonging the total isovolumic time (t-IVT). METHODS: A total of 59 patients with DCM-34 with CAD (20 normal activation [NA], 14 LBBB) and 25 without CAD (15 NA, 10 LBBB)-were studied. The total IVT (s/min; calculated as: 60 - [total ejection time + total filling time] ) and CO were measured by Doppler echocardiography. RESULTS: At rest, t-IVT was 8 s/min longer with LBBB (p < 0.001), was unaffected by CAD, and did not correlate with rest CO. During stress, CO correlated with t-IVT (r = -0.73, p < 0.001) in all four patient groups. In the absence of CAD, t-IVT became shortened (NA by 7 +/- 3 s/min; LBBB by 9 +/- 4 s/min) and correlated with a fall in the QRS duration (NA: r = 0.87; LBBB: r = 0.91), and CO increased with stress (NA by 4.7 +/- 2.7 l/min; LBBB by 4.0 +/- 2.3 l/min; all p < 0.001). With CAD, t-IVT did not shorten normally with stress. Instead, t-IVT was 5.6 s/min longer and CO was 3.3 l/min lower than in those without CAD (both p < 0.001), and t-IVT did not correlate with the QRS duration. CONCLUSIONS: In patients with DCM, t-IVT during pharmacologic stress depends on changes in ventricular activation induced by LBBB or CAD and is, by itself, a major determinant of peak CO during stress.
Asunto(s)
Bloqueo de Rama/diagnóstico por imagen , Bloqueo de Rama/fisiopatología , Gasto Cardíaco/efectos de los fármacos , Gasto Cardíaco/fisiología , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/fisiopatología , Ecocardiografía de Estrés/métodos , Anciano , Bloqueo de Rama/complicaciones , Volumen Cardíaco/efectos de los fármacos , Volumen Cardíaco/fisiología , Cardiomiopatía Dilatada/complicaciones , Fenómenos Fisiológicos Cardiovasculares/efectos de los fármacos , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/fisiopatología , Ecocardiografía Doppler , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
BACKGROUND: The mechanism for reduced early diastolic long axis lengthening velocity in hypertrophic cardiomyopathy (HCM) is not known. METHODS: We measured simultaneous septal long axis amplitude and early lengthening velocity in 23 patients with HCM, 23 normal subjects and 22 patients with coronary artery disease (CAD) of left anterior descending artery. RESULTS: Resting amplitude and lengthening velocity were reduced in HCM 0.9+/-0.2 cm, 3.5+/-1.9 cm/s but equally in CAD 1.0+/-0.3 cm, 4.1+/-2.5 cm/s vs. 1.3+/-0.2 cm, 6.3+/-1.7 cm/s in normals, p < 0.01 for both vs. normal. With dobutamine stress, lengthening velocity increased by 2.7+/-1.9 cm/s (p < 0.001) in normals, by 2.8+/-2.5 cm/s (p < 0.001) in HCM but not in patients with CAD 0.5+/-2.1, p = NS. Increment in total long axis amplitude was subnormal in CAD and HCM. However, increment in lengthening velocity was higher with stress for corresponding change in amplitude in HCM compared with CAD (chi2) = 16.5, p < 0.001). An increase in early lengthening velocity by 2 cm/s was 77% sensitive and 70% specific in discriminating between HCM and CAD. Post-ejection shortening developed or worsened in all CAD patients indicating ischemia but not in any with HCM. CONCLUSIONS: Reduced peak early lengthening velocity is not specific for HCM but also occurs in CAD. Unlike CAD, lengthening velocity increases in HCM with stress and there is no aggravation of post-ejection shortening, suggesting that the abnormal relaxation is not due to subendocardial ischemia in HCM. The greater recoil velocity per unit deformation in HCM compared with CAD, indicates elastic mechanism with increased passive muscle stiffness due to fibrosis or fibre disarray.
Asunto(s)
Cardiomiopatía Hipertrófica/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Ecocardiografía de Estrés , Ventrículos Cardíacos/fisiopatología , Cardiomiopatía Hipertrófica/fisiopatología , Estudios de Casos y Controles , Enfermedad de la Arteria Coronaria/fisiopatología , Diástole/fisiología , Femenino , Tabiques Cardíacos/diagnóstico por imagen , Tabiques Cardíacos/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y EspecificidadRESUMEN
OBJECTIVES: To assess the effect of atrial flutter (AFL) on exercise tolerance in patients with grown-up congenital heart (GUCH), exercise tests with modified Bruce protocol were performed in 20 patients aged 21 to 62 years with GUCH (11 females, 9 males) during symptomatic AFL and again 24 to 48 hours after DC conversion to sinus rhythm (SR). At the same time, cardiac function was assessed by means of transthoracic Doppler echocardiography. RESULTS: Mean exercise duration was significantly less during AFL (6.4 +/- 4.1 min) versus SR (10.9 +/- 3.7 min) (P <.001). Heart rate was faster at rest and peak exercise while in AFL (106 +/- 21 beats/min vs 77 +/- 14 beats/min, P <.001, and 157 +/- 31 beats/min vs 129 +/- 24 beats/min, P <.01, respectively). Systolic blood pressure was lower at peak exercise with AFL (112 +/- 25 mm Hg vs 137 +/- 24 mm Hg, P <.001), as was mean blood pressure increase (5.3 +/- 24.3 mm Hg vs 22.6 +/- 15.8 mm Hg) compared with SR (P <.01). Four of the 6 patients after Fontan surgery had a decrease of 16 mm Hg in systolic blood pressure at peak exercise when in AFL. The reasons for exercise termination during AFL were mainly breathlessness, chest pain, or presyncope, whereas in SR it was caused by fatigue. Echocardiography during AFL showed shorter isovolumic relaxation time (40 +/- 20 ms) compared with SR (50 +/- 20 ms) (P <.05). Ventricular long-axis excursion was reduced (left 1.0 +/- 0.3 cm vs 1.2 +/- 0.4 cm, septal 0.5 +/- 0.2 cm vs 0.7 +/- 0.3 cm, and right 0.7 +/- 0.2 cm vs 0.9 +/- 0.4 cm respectively, P <.001 for all), as were peak pulmonary and aortic flow velocities (85 +/- 30 cm/s vs 105 +/- 50 cm/s, P <.001, and 137 +/- 118 cm/s vs 143 +/- 114 cm/s, P <.02) compared with sinus rhythm. There was a close correlation between exercise duration and blood pressure increase (r = 0.6), left-sided long-axis excursion and blood pressure increase (r = 0.57), and between aortic flow velocity and right-sided long-axis excursion (r = 0.71). CONCLUSIONS: Atrial flutter causes dramatic reduction in exercise tolerance in patients with GUCH, and the combination of fast heart rate and hypotension may contribute to the development of presyncope, particularly in those with Fontan surgery. Marked improvement in effort tolerance and cardiac dynamics occurs after regaining SR. Thus, improving the quality of life in patients with GUCH requires maintaining SR.
Asunto(s)
Aleteo Atrial/fisiopatología , Tolerancia al Ejercicio , Cardiopatías Congénitas/fisiopatología , Frecuencia Cardíaca/fisiología , Adulto , Aleteo Atrial/terapia , Presión Sanguínea/fisiología , Ecocardiografía , Femenino , Procedimiento de Fontan , Humanos , Masculino , Persona de Mediana Edad , Calidad de Vida , SístoleRESUMEN
BACKGROUND: The absence of electrocardiographic septal q wave is a recognized marker of left ventricular disease. We aimed to investigate the prognostic significance of absent septal q waves in elderly (age >65 years) patients with chronic heart failure. METHODS: A total of 110 patients (mean age 73 +/- 4 years) with New York Heart Association functional class II to IV and left ventricular ejection fraction of <45% were enrolled in the study. Standard 12-lead electrocardiograms were critically analyzed for the presence or absence of septal q waves in leads I, aVL, V5, and V6. Patient survival was determined from hospital and general practitioner records and National Statistics Registry at a mean follow-up of 4 years. RESULTS: Septal q waves were absent in 71 and present in 39 patients. The overall mortality rate was 47% (43 patients). The incidence of death was 49% (36 patients) in the group with no septal q waves and 18% (7 patients) in those who demonstrated septal q waves. On univariate analysis by Cox proportional hazard method, absence of septal q waves was found to be a strong marker of poor prognosis in CHF (P =.003, hazard ratio 1.40, 95% CI 1.10-1.67). Kaplan-Meier survival curves showed a significant difference in survival independent of age, New York Heart Association functional class, peak VO2, and QRS duration between these 2 groups. CONCLUSIONS: Absence of the normal septal q wave on 12-lead electrocardiography, which may indicate structural heart disease and myocardial fibrosis, is an independent predictor of poor prognosis in elderly patients with CHF.
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Electrocardiografía , Insuficiencia Cardíaca/fisiopatología , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Enfermedad Crónica , Estudios de Seguimiento , Insuficiencia Cardíaca/mortalidad , Tabiques Cardíacos/fisiología , Humanos , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Volumen Sistólico , Análisis de SupervivenciaRESUMEN
AIMS: The purpose of this study was to compare the noninvasive assessment of severity of pulmonary regurgitation with Doppler echocardiography versus cardiovascular magnetic resonance imaging (CMR) in adult patients with repaired tetralogy of Fallot (rTOF). METHODS: We studied 52 (22 females) consecutive patients (aged 32 +/- 2 years, 23 +/- 5 years after rTOF) using Doppler echocardiography and compared these findings with CMR. From the continuous-wave Doppler trace, the duration of pulmonary regurgitation and of total diastole was measured and the ratio between the 2 was defined as pulmonary regurgitation index (PRi). Pulmonary regurgitant fraction (PRF) was assessed with flow phase velocity mapping with CMR. RESULTS: Patients were divided into 2 groups according to the median value (24.5%) of PRF measured by CMR: Group I (26 patients) with PRF < or =24.5% and Group II with PRF >24.5%. There was no difference between patients' age, sex, or age at repair between the 2 groups. More patients from Group II had a right ventricular outflow or transannular patch repair compared to Group I (12/26 [46%] vs 6/26 [23%], P <.01). Mean pulmonary regurgitation time was shorter (340 +/- 60 vs 440 +/- 135 ms, P =.001) and PRi was lower (0.61 +/- 0.11 vs 0.91 +/- 0.11, P <.001) in Group II compared to Group I. Color Doppler regurgitant jet was also broader in Group II (1.4 +/- 0.4 vs 0.7 +/- 0.5 cm, P <.001), signifying more severe pulmonary regurgitation. Doppler-measured PRi correlated closely with CMR regurgitant fraction (r = -0.82, P <.001) and with color Doppler pulmonary regurgitant jet width (r = -0.66, P <.001); the latter correlated with PRF assessed with CMR (r = 0.72, P <.001). A PRi <0.77 had 100% sensitivity and 84.6% specificity for identifying patients with pulmonary regurgitant fraction >24.5%, with a predictive accuracy of 95%. Furthermore, echocardiographically-assessed right ventricular end-diastolic dimensions correlated with CMR end-diastolic volume index (r = 0.49, P <.001 ). CONCLUSIONS: Pulmonary regurgitation is common in asymptomatic adults with rTOF. Severity of pulmonary regurgitation and its effects on right ventricular dimensions in these patients can be assessed noninvasively by Doppler echocardiography and CMR, with reasonable agreement between the 2 techniques.
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Ecocardiografía Doppler , Imagen por Resonancia Magnética , Complicaciones Posoperatorias/diagnóstico , Insuficiencia de la Válvula Pulmonar/diagnóstico , Tetralogía de Fallot/cirugía , Adulto , Diástole , Ecocardiografía Doppler/métodos , Femenino , Humanos , Masculino , Complicaciones Posoperatorias/diagnóstico por imagen , Insuficiencia de la Válvula Pulmonar/diagnóstico por imagen , Insuficiencia de la Válvula Pulmonar/fisiopatología , Estenosis de la Válvula Pulmonar/diagnóstico , Estenosis de la Válvula Pulmonar/diagnóstico por imagen , Estenosis de la Válvula Pulmonar/fisiopatología , Análisis de Regresión , Estadísticas no Paramétricas , Tetralogía de Fallot/diagnóstico por imagen , Factores de Tiempo , Disfunción Ventricular Derecha/diagnóstico , Disfunción Ventricular Derecha/diagnóstico por imagen , Disfunción Ventricular Derecha/fisiopatologíaRESUMEN
BACKGROUND: Pharmacological stress is used to assess the degree of left ventricular (LV) subvalvular gradient in patients with hypertrophic cardiomyopathy (HCM), but there is little information about associated physiological changes. METHODS: Echocardiography-Doppler ultrasound scanning measurements in 23 patients with HCM and 23 control subjects of similar age were studied at rest and at the end point of dobutamine stress. RESULTS: In patients, the systolic time was normal at rest, but increased abnormally with stress. In patients, the total isovolumic contraction time failed to shorten, and the total ejection time increased abnormally. Changes in total ejection time correlated with an increase in peak subvalvular gradient in control subjects and patients (r = 0.52 and r = 0.66, respectively; P <.01 for both). In patients, the diastolic time was normal at rest, but shortened abnormally with stress. In patients, the isovolumic relaxation time fell abnormally, as did the filling time. Mitral E wave acceleration and left atrium size were unchanged with stress in control subjects, but consistently increased in patients with HCM, which indicates an increased early diastolic atrioventricular pressure gradient. CONCLUSION: In HCM, systolic period increases abnormally with stress. This is not because of a loss of inotropy, but is directly related to the degree of LV outflow tract obstruction. As a result, the diastolic period fails to increase, reducing the time available for coronary flow, the LV filling pattern is modified, and the diastolic atrioventricular pressure gradient increases. These changes may contribute to symptom development and suggest why reducing LV outflow tract obstruction per se may be therapeutically useful in HCM.
Asunto(s)
Cardiomiopatía Hipertrófica/fisiopatología , Obstrucción del Flujo Ventricular Externo/fisiopatología , Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/diagnóstico por imagen , Estudios de Casos y Controles , Diástole , Ecocardiografía Doppler , Ecocardiografía de Estrés , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico , Sístole , Obstrucción del Flujo Ventricular Externo/etiologíaRESUMEN
BACKGROUND: Pulsed Wave Tissue Doppler (PWTD) recording of myocardial velocities has been widely used for assessing ventricular function but the output trace has finite thickness that leads to potential ambiguity in determining velocity and timing. OBJECTIVE: To determine optimal method of measurement of PWTD traces by comparing them with those obtained from digitised M-mode recorded from the atrioventricular (AV) valve ring (septal, LV and RV free wall). METHODS: We studied 100 subjects, 49 normal and 51 with coronary artery disease (15 patients with reduced left ventricular wall motion, mean systolic amplitude of LV free wall 0.8+/-0.3 cm), mean age 53+/-15 years. We recorded AV ring motion using PWTD and M-mode echo techniques. PWTD velocity signals were measured separately at: outer, inner and mid-points of the envelope and compared with peak velocities obtained from digitised M-mode long axis. RESULTS: Peak systolic (S), early diastolic (E) and late diastolic (A) PWTD velocities at outer, inner and middle envelope correlated closely with the corresponding M-mode measurements at left, septal and right ventricular free wall. However, only the midpoint S and E wave PWTD signal velocities agreed numerically with those obtained by digitised M-mode velocities; S (left 6.56+/-1.80 vs. 6.54+/-1.91 cm/s N.S.); E (left 8.50+/-3.25 vs. 7.65+/-3.30 cm/s N.S.). Agreement was somewhat less satisfactory for A wave; left 7.40+/-2.13 vs. 6.23+/-2.09 cm/s p<0.05. CONCLUSION: Atrioventricular valve ring echo provides an excellent in vivo calibration model for validating tissue Doppler velocity estimates. Since the mid-point of the envelope of the tissue Doppler signal is the most closely related value to that of the digitised M-mode, it may be recommended as a convention for routine practice.
Asunto(s)
Fascículo Atrioventricular/diagnóstico por imagen , Ecocardiografía Doppler de Pulso , Ventrículos Cardíacos/diagnóstico por imagen , Contracción Miocárdica/fisiología , Adolescente , Adulto , Anciano , Fascículo Atrioventricular/fisiopatología , Calibración , Estudios de Casos y Controles , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: The Tei index is commonly used as a measure of "combined systolic and diastolic function". A sensitive and specific index of intrinsic myocardial contraction and relaxation would be independent of abnormal activation. We aimed to determine whether the Tei index fulfils this criterion in patients with normal activation or left bundle branch block (LBBB), normal or dilated left ventricular (LV) cavities, with or without coronary artery disease (CAD). METHODS: We studied 32 controls and 124 patients; 49 had CAD and normal LV size (11 LBBB), 27 had non-ischaemic dilated cardiomyopathy (DCM, 11 LBBB), and 48 had ischaemic DCM (17 LBBB). Tei index (isovolumic contraction time+isovolumic relaxation time/ejection time) and total isovolumic time (t-IVT: [60-(total ejection time+total filling time]) were measured using Doppler echocardiography. RESULTS: Tei index and t-IVT were prolonged in LBBB (by 0.6 and 9.1 s/min, P<0.001). T-IVT identified LBBB with greater predictive accuracy than Tei index (sensitivity 97% vs. 90%, specificity 93% vs. 91%, P<0.05). Tei index and t-IVT were also prolonged in DCM (by 0.2 and 3.1 s/min, both P<0.001). Although Tei index identified DCM with sensitivity 71%, this fell to 53% when LBBB was excluded (P<0.05). CAD had no effect on Tei index or t-IVT. CONCLUSIONS: The Tei index is not a measure of intrinsic myocardial systolic and diastolic function, since its main determinant is ventricular activation rather than cavity size. T-IVT, however, is more sensitive to activation, is unrelated to cavity size or CAD, and may thus be a more accurate measure of the mechanical consequences of ventricular activation in a variety of cardiac conditions.
Asunto(s)
Bloqueo de Rama/diagnóstico , Cardiomiopatía Dilatada/diagnóstico , Pruebas de Función Cardíaca/métodos , Contracción Miocárdica , Disfunción Ventricular Izquierda/diagnóstico , Anciano , Análisis de Varianza , Estudios de Casos y Controles , Enfermedad Coronaria/diagnóstico , Ecocardiografía Doppler , Femenino , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Masculino , Persona de Mediana Edad , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Volumen SistólicoRESUMEN
BACKGROUND: The exact location of a Q wave myocardial infarction has an important effect on overall left ventricular function. OBJECTIVES: To assess the effect of localization of Q wave infarction on left ventricular minor and long axis function, with particular reference to electromechanical disturbances. METHODS: We studied 72 patients with Q wave myocardial infarction; 35 anterior, age 61+/-15 years and 37 inferior, age 62+/-12 years. ECG intervals were automatically measured by Hewlett-Packard Pagewriter and LV dimension and filling velocities studied by transthoracic echocardiography and simultaneous phonocardiogram. Findings were compared with 21 controls of similar age. RESULTS: Heart rate and all ECG intervals were similar in the two patient groups and controls. QRS axis was more to the left in patients with inferior MI. Normal septal q wave was absent in lead V5 and V6 in 33/35 (94%) patients with anterior MI and in only 3/37 (8%) with inferior MI, p<0.001. LV minor axis dimensions were enlarged vs. normal (p<0.001) in the two patient groups and to a greater extent in anterior MI compared with inferior MI, p<0.05. Isovolumic relaxation time was prolonged only in-patients with an inferior MI, p<0.01. Long axis amplitude was globally reduced (p<0.001) in the two patient groups as were shortening and lengthening velocities (p<0.001). The onset of septal long axis shortening with respect to the q wave was delayed by 30 and 40 ms in inferior MI and anterior MI and that of lengthening with respect to A2 by 20 and 30 ms, respectively, compared to normal (p<0.001 for both). Post ejection shortening was localized to the septal long axis in 32/35 patients with anterior MI but was generalized involving all three LV long axes in inferior MI, p<0.001. Transmitral Doppler flow velocities and the frequency of mild mitral regurgitation were similar in the two groups. CONCLUSION: These results confirm a close association between anterior Q wave infarction, septal incoordination and absent septal q waves. The global incoordinate long axis behaviour in inferior Q wave MI may be due to significant papillary muscle dysfunction, and results in significant shape change in early diastole. This disturbance in electromechanical behaviour might play an important role in the differing outcomes between the two different sites of myocardial infarction.
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Fenómenos Biomecánicos , Electrocardiografía , Electrofisiología , Infarto del Miocardio/fisiopatología , Función Ventricular Izquierda/fisiología , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Diástole/fisiología , Ecocardiografía , Femenino , Frecuencia Cardíaca/fisiología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Sístole/fisiologíaRESUMEN
BACKGROUND AND AIM OF THE STUDY: Although severe tricuspid regurgitation (TR) is a well-recognized, long-term complication of rheumatic mitral valve replacement that impairs the functional results of surgery, its exact basis remains unclear and its management is unsatisfactory. The study aim was to obtain a detailed assessment of tricuspid valve morphology and function using 2D transesophageal echocardiography (TEE) with 3D reconstruction, and to determine long-term clinical outcome in patients after surgery for rheumatic mitral valve disease. METHODS: A total of 42 patients (mean age 50 +/- 10 years) was followed up; 39 patients had mitral replacement and three had valvotomy. Thirty patients had developed impaired exercise tolerance, fluid retention and echocardiographic evidence of severe TR at 8.2 +/- 2.6 years after surgery; the remainder had mild regurgitation. RESULTS: Follow up showed greater mortality in the severe TR group, with approximately 50% survival at 60 months after diagnosis compared with mild TR. None of the patients with severe TR had a dysfunctional mitral prosthesis. In these patients, transthoracic echo-Doppler showed enlarged right atrium and right ventricle, a mean transtricuspid retrograde pressure drop of 15 +/- 4 mmHg and apparently normal leaflet anatomy. Twenty patients (15 with severe TR) underwent a TEE and 3D reconstruction study for further evaluation. Abnormal leaflet anatomy was demonstrated in all patients with severe TR, with restricted leaflet motion in 10, leaflet shortening and thickening in the remainder, and dilatation of tricuspid valve annular insertion suggestive of rheumatic involvement. Although diastolic transtricuspid velocities were increased (peak flow 0.8 +/- 0.1 m/s) in these patients due to increased stroke volume, significant tricuspid stenosis was present in only two cases (mean gradient 4 and 3 mmHg respectively). Histopathology confirmed the presence of leaflet vascularization and extensive fibrosis in two patients who underwent tricuspid valve replacement. CONCLUSION: Rheumatic leaflet involvement contributes to severe TR occurring long after mitral valve replacement, though overt stenosis is uncommon. Knowledge of the structural basis of this condition may thus improve its long-term management, possibly with early tricuspid valve repair.
Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas , Válvula Mitral/patología , Válvula Mitral/cirugía , Cardiopatía Reumática/diagnóstico por imagen , Cardiopatía Reumática/etiología , Insuficiencia de la Válvula Tricúspide/diagnóstico por imagen , Insuficiencia de la Válvula Tricúspide/etiología , Adulto , Velocidad del Flujo Sanguíneo/fisiología , Calcinosis/diagnóstico por imagen , Calcinosis/etiología , Calcinosis/mortalidad , Diástole/fisiología , Ecocardiografía Doppler , Ecocardiografía Tridimensional , Ecocardiografía Transesofágica , Estudios de Seguimiento , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/mortalidad , Cardiopatía Reumática/mortalidad , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Sístole/fisiología , Resultado del Tratamiento , Válvula Tricúspide/diagnóstico por imagen , Válvula Tricúspide/patología , Válvula Tricúspide/cirugía , Insuficiencia de la Válvula Tricúspide/mortalidad , Estenosis de la Válvula Tricúspide/diagnóstico por imagen , Estenosis de la Válvula Tricúspide/etiología , Estenosis de la Válvula Tricúspide/mortalidadRESUMEN
OBJECTIVE: In patients with coronary artery disease (CAD), the normal electromechanical response to dobutamine stress is deranged: QRS duration lengthens rather than shortens, left ventricular asynchrony develops, post-ejection shortening appears, and total isovolumic time (the time in the cardiac cycle when the ventricle is neither ejecting nor filling) increases rather than falls, all of which blunt the normal rise in cardiac output. We aimed to study the effect of revascularisation on these stress-induced electromechanical abnormalities and their effect on peak cardiac output after coronary artery bypass grafting (CABG). METHOD: 20 unselected patients were studied before and after CABG. Long axis asynchrony was determined by (i) delay in the onset of shortening, (ii) amplitude and (iii) duration of post-ejection shortening. Total isovolumic time (in s/min), calculated as [60-(total ejection time+total filling time)] and cardiac output were measured by Doppler echocardiography. RESULTS: Before CABG: QRS duration broadened with stress (by 7+/-8 ms, P<0.01) and post-ejection shortening increased (amplitude by 1.1+/-0.7 mm, P<0.01, duration by 8+/-9 ms, P<0.01). Total isovolumic time increased (by 3+/-3 s/min, P<0.01) and cardiac output rose (by 2.8+/-1.2 l/min, P<0.01). After CABG: QRS duration shortened with stress (by 5+/-4 ms, P<0.01) post-ejection shortening decreased (amplitude and duration fell by 0.4+/-0.5 mm and 22+/-14 ms, respectively), total isovolumic time shortened (by 3+/-3 s/min) and cardiac output increased (by 5.1+/-1.8 l/min, all P<0.01). Changes in total isovolumic time and duration of post-ejection shortening with stress were independent predictors of the increase in peak cardiac output after revascularisation (total R(2)=0.69). Independent predictors of changes in total isovolumic time with stress were those in QRS duration and the duration of post-ejection shortening (total R(2)=0.75). In turn, changes in the duration of post-ejection shortening were closely associated with alterations in the delay in long axis shortening (r(2)=0.50) which correlated with changes in QRS duration (r(2)=0.59, all P<0.001). CONCLUSIONS: Revascularisation resynchronises left ventricular wall motion by restoring the normal activation response to stress, thereby reducing total isovolumic time and normalising peak cardiac output response to stress.
Asunto(s)
Puente de Arteria Coronaria , Disfunción Ventricular Izquierda/fisiopatología , Anciano , Gasto Cardíaco , Cardiotónicos , Dobutamina , Ecocardiografía Doppler/métodos , Electrocardiografía , Femenino , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/fisiopatología , Periodo Posoperatorio , Estudios Prospectivos , Disfunción Ventricular Izquierda/diagnóstico por imagenRESUMEN
OBJECTIVE: Echocardiography is widely considered the gold standard for the diagnosis of tamponade. While a relatively common complication of cardiac surgery in adults, determining whether haemodynamics are compromised by a pericardial collection early post-operatively can be difficult. The aim of the current study was to determine the nature and magnitude of the diagnostic challenge posed by cardiac tamponade following cardiac surgery. We therefore examined the accuracy of echocardiography in the diagnosis of tamponade in this patient group. METHODS: From January 2000 to January 2002, 2297 adult patients underwent cardiac surgery in a tertiary referral cardiothoracic centre. A retrospective analysis of prospectively collected data, from all patients diagnosed with post-operative bleeding and/or tamponade was performed. Data included demographics, surgery, anticoagulation/anti-platelet medication, clinical/echocardiographic features of tamponade and surgical findings at re-exploration. RESULTS: The diagnosis of 'tamponade' was confirmed at re-exploration in 148 patients. When it occurred early (<72 h) following cardiac surgery trans-thoracic echocardiography failed to visualise the majority of collections (60%), necessitating trans-esophageal echocardiography. Effusions were small (160+/-17 ml) and localised (92%), showing no echocardiographic features of classical tamponade (79%). Where patients developed tamponade late (>72 h) following cardiac surgery, clinical features were atypical, effusions larger (640+/-71 ml, P<0.0001)) and global (77%). Classical echocardiographic features of tamponade were usually present (70%) and readily visualised using trans-thoracic echocardiography. CONCLUSIONS: Haemodynamically significant pericardial collections occurring early following cardiac surgery rarely cause classical clinical or echocardiographic features of tamponade. Recognition of this as a separate diagnostic entity is necessary to ensure appropriate surgical intervention is not delayed.
Asunto(s)
Procedimientos Quirúrgicos Cardíacos/efectos adversos , Taponamiento Cardíaco/diagnóstico por imagen , Ecocardiografía/métodos , Complicaciones Posoperatorias/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Procedimientos Quirúrgicos Cardíacos/métodos , Taponamiento Cardíaco/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Terminología como AsuntoRESUMEN
OBJECTIVES: Many patients with coronary artery disease demonstrate chronic resting ischaemic myocardial dysfunction. We have investigated whether this ischaemia influences the myocardial damage caused by the period of coronary occlusion involved in beating heart surgery. METHODS: Thirty-three patients with chronic stable angina and normal left ventricular ejection fraction were studied. To make our model clinically appropriate, we included patients with a wide range of ischaemic times, ages and in a subset of 10 patients a surgical preconditioning protocol. Myocyte injury was assessed from venous Troponin T release measured on days 1, 2, and 3. We used intraoperative transoesophageal M mode echocardiograms and simultaneous high-fidelity left ventricular pressure to assess whether patients were demonstrating the functional effects of ischaemia (asynchronous regional contraction with reduced mechanical function). RESULTS: Patients demonstrated the functional effects of resting ischaemia and 17 did not. Patients with resting ischaemia had lower preoperative values of regional peak power and work and all three variables increased significantly with surgery. Venous Troponin T levels at 48 and 72 h postoperatively were lower in those with preoperative resting ischaemia (median (interquartile range) 0.13 (0.08-0.20) vs 0.21 (0.13-0.69) for 48 h and 0.10 (0.08-0.19) vs 0.26 (0.12-0.51) for 72 h). Stepwise multiple linear regression of total postoperative troponin release (measured as the area under the curve of troponin release) demonstrated two independent determinants (R squared for model 0.40): longer ischaemic time, and increasing values of cycle efficiency. The surgical ischaemic preconditioning protocol and preoperative collaterals were not independent determinants. CONCLUSIONS: In patients with chronic coronary artery disease, stable preoperative ischaemia may thus represent a naturally occurring form of myocardial protection, whose presence reduces Troponin T release after beating heart surgery. This protection is different in nature from classical ischaemic preconditioning.
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Puente de Arteria Coronaria/métodos , Enfermedad Coronaria/cirugía , Precondicionamiento Isquémico Miocárdico , Células Musculares/patología , Anciano , Puente Cardiopulmonar , Circulación Colateral , Ecocardiografía Transesofágica/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios/métodos , Troponina T/sangre , Función Ventricular IzquierdaRESUMEN
Nonsurgical septal reduction has been proposed as a means of treating patients with hypertrophic cardiomyopathy whose symptoms of exercise limitation by chest pain or breathlessness are inadequately controlled with standard medical therapy (i.e., beta blockers, calcium antagonists, or even DDD pacing).