Presence of obesity is associated with lower mortality in elderly patients with implantable cardioverter defibrillator.

BACKGROUND: Higher body mass index (BMI) is associated with greater prevalence of cardiovascular risk factors, yet an inverse relationship between obesity and survival after cardiovascular events has been described. It is unclear whether a similar relationship exists for patients with implantable cardioverter defibrillators (ICDs) at high risk for mortality. We aimed to assess the impact of BMI on mortality and cardiovascular hospitalization in patients with ICD. METHODS: Patients who underwent ICD implantation in 2010-2011 were divided into normal (<25 kg m-2), overweight (25-29.9 kg m-2) and obese (⩾30 kg m-2) groups based on BMI. Clinical parameters were compared and long-term outcomes were determined using χ2 test, Wilcoxon's rank-sum test, logistic regression models and Kaplan-Meier curves. RESULTS: Of 904 patients (mean age 67±13 years), 26% had normal BMI, 32% were overweight and 42% were obese. No significant baseline differences in ventricular ejection fraction, ICD for primary or secondary prevention, history of heart failure, syncope or cardiac arrest existed. Despite a greater prevalence of diabetes, hypertension and prior myocardial infarction, the obese and overweight groups had lower mortality (10.1% and 7.9%, respectively) than the normal group (22.9%, P<0.001). On multivariate logistic regression, BMI in the obese and overweight range (odds ratio (OR): 0.35; 95% confidence interval (CI): 0.21-0.58 and OR: 0.25; 95% CI: 0.13-0.40, respectively) was protective against mortality, whereas history of diabetes (OR: 2.01; 95% CI: 1.30-3.09), myocardial infarction (OR: 1.76; 95% CI: 1.11-2.80), heart failure (OR: 3.88; 95% CI: 1.56-9.66), stroke (OR: 3.19; 95% CI: 1.63-6.23) and history of cardiac arrest (OR: 2.65; 95% CI: 1.37-5.15) were independent risk factors for higher mortality. CONCLUSIONS: A paradoxical relationship between BMI and mortality risk is present in elderly patients with ICD at high risk of sudden death with a lower mortality in obese or overweight patients than in those with normal BMI.

Determinants of the degree of functional mitral regurgitation in patients with systolic left ventricular dysfunction: A quantitative clinical study.

BACKGROUND: Functional mitral regurgitation (FMR) occurs with a structurally normal valve as a complication of systolic left ventricular dysfunction (LVD). Determinants of degree of FMR are poorly defined; thus, mechanistic therapeutic approaches to FMR are hindered. METHODS AND RESULTS: In a prospective study of 21 control subjects and 128 patients with LVD (defined as ejection fraction <50%, mean 31+/-9%) in sinus rhythm, we quantified simultaneously by echocardiography the effective regurgitant orifice (ERO) of FMR by using 2 methods: mitral deformation (valve and annulus) and left ventricular (LV) global (volumes, stress, function, and sphericity) and local (papillary muscle displacements and regional wall motion index) remodeling. A wide range of ERO (15+/-14 mm(2), 0 to 87 mm(2)) was observed, unrelated to ejection fraction (P:=0.32). The major determinant of ERO was mitral deformation, ie, systolic valvular tenting and annular contraction in univariate (r=0.74 and r=-0.61, respectively; both P:<0.0001) and multivariate (both P:<0. 0001) analyses, independent of global LV remodeling. Systolic valvular tenting was strongly determined by local LV alterations, particularly apical (r=0.75) and posterior (r=0.70) displacement of papillary muscle, with confirmation in multivariate analysis (both P:<0.0001), independent of LV volumes, function, and sphericity. CONCLUSIONS: The presence and degree of FMR complicating LVD are unrelated to the severity of LVD. Local LV remodeling (apical and posterior displacement of papillary muscles) leads to excess valvular tenting independent of global LV remodeling. In turn, excess tenting and loss of systolic annular contraction are associated with larger EROs. These determinants of FMR warrant consideration for specific approaches to the treatment of FMR complicating LVD.

Ischemic mitral regurgitation: long-term outcome and prognostic implications with quantitative Doppler assessment.

BACKGROUND: Myocardial infarction (MI) can directly cause ischemic mitral regurgitation (IMR), which has been touted as an indicator of poor prognosis in acute and early phases after MI. However, in the chronic post-MI phase, prognostic implications of IMR presence and degree are poorly defined. METHODS AND RESULTS: We analyzed 303 patients with previous (>16 days) Q-wave MI by ECG who underwent transthoracic echocardiography: 194 with IMR quantitatively assessed in routine practice and 109 without IMR matched for baseline age (71+/-11 versus 70+/-9 years, P=0.20), sex, and ejection fraction (EF, 33+/-14% versus 34+/-11%, P=0.14). In IMR patients, regurgitant volume (RVol) and effective regurgitant orifice (ERO) area were 36+/-24 mL/beat and 21+/-12 mm(2), respectively. After 5 years, total mortality and cardiac mortality for patients with IMR (62+/-5% and 50+/-6%, respectively) were higher than for those without IMR (39+/-6% and 30+/-5%, respectively) (both P<0.001). In multivariate analysis, independently of all baseline characteristics, particularly age and EF, the adjusted relative risks of total and cardiac mortality associated with the presence of IMR (1.88, P=0.003 and 1.83, P=0.014, respectively) and quantified degree of IMR defined by RVol >/=30 mL (2.05, P=0.002 and 2.01, P=0.009) and by ERO >/=20 mm(2) (2.23, P=0.003 and 2.38, P=0.004) were high. CONCLUSIONS: In the chronic phase after MI, IMR presence is associated with excess mortality independently of baseline characteristics and degree of ventricular dysfunction. The mortality risk is related directly to the degree of IMR as defined by ERO and RVol. Therefore, IMR detection and quantification provide major information for risk stratification and clinical decision making in the chronic post-MI phase.

Assessment of severity of aortic regurgitation using the width of the vena contracta: A clinical color Doppler imaging study.

BACKGROUND: The width of the vena contracta (VC-W), the smallest area of regurgitant flow, reflects the degree of valvular regurgitation and is measurable by color Doppler imaging, but this method has not been validated in aortic regurgitation (AR). METHODS AND RESULTS: We prospectively examined 79 patients with isolated AR and 80 patients without regurgitation. The VC-W was measured from the long-axis parasternal view and compared with 2 simultaneous reference methods (quantitative Doppler and 2D echocardiography). In patients without regurgitation, the agreement between methods was excellent. In patients with AR, good correlations (all P<0.0001) were obtained between VC-W and effective regurgitant orifice (ERO) area and regurgitant volume recorded by quantitative Doppler (r=0.89 and 0.90, respectively) and 2D echocardiographic (r=0.90 and 0.89, respectively) methods. These correlations were similar with eccentric or central jets (all P>0.60). The other methods used showed good correlations of VC-W with aortographic grading of AR (n=8, r=0.82, P=0.01), with the proximal flow convergence method (n=53, r=0.85, P<0.0001), and with left ventricular end-diastolic volume (r=0.81, P<0.0001). Sensitivity and specificity of VC-W >/=6 mm for diagnosing severe AR (ERO >/=30 mm(2)) were 95% and 90%, respectively. CONCLUSIONS: For assessment of the degree of AR, VC-W shows good correlations with simultaneous quantitative measures (regardless of jet direction), shows good correlations with other methods of assessment of AR, and provides a high diagnostic value for severe AR. VC-W is a simple, reliable method that can be used clinically as part of comprehensive Doppler echocardiographic assessment of AR.

Clinical profile and outcome of idiopathic restrictive cardiomyopathy.

BACKGROUND: Idiopathic restrictive cardiomyopathy is a poorly recognized entity of unknown cause characterized by nondilated, nonhypertrophied ventricles with diastolic dysfunction resulting in dilated atria and variable systolic function. METHODS AND RESULTS: Between 1979 and 1996, 94 patients (61% women) 10 to 90 years old (mean, 64 years) met strict morphological echocardiographic criteria for idiopathic restrictive cardiomyopathy, mainly dilated atria with nonhypertrophied, nondilated ventricles. None had known infiltrative disease, hypertension of >5 years' duration, or cardiac or systemic conditions associated with restrictive filling. Nineteen percent were in NYHA class I, 53% in class II, and 28% in class III or IV. Atrial fibrillation was noted in 74% of patients and systolic dysfunction in 16%. Follow-up (mean, 68 months) was complete for 93 patients (99%). At follow-up, 47 patients (50%) had died, 32 (68%) of cardiovascular causes. Four had heart transplantation. The death rate compared with actuarial statistics was significantly higher than expected (P<0.0001). Kaplan-Meier 5-year survival was 64%, compared with expected survival of 85%. Multivariate analysis using proportional hazards showed that the risk of death approximately doubles with male sex (hazard ratio [HR] = 2.1), left atrial dimension >60 mm (HR = 2.3), age >70 years (HR = 2.0), and each increment of NYHA class (HR = 2.0). CONCLUSIONS: Idiopathic restrictive cardiomyopathy or nondilated, nonhypertrophic ventricles with marked biatrial dilatation, as defined morphologically by echocardiography, affects predominantly elderly patients but can occur in any age group. Patients present with systemic and pulmonary venous congestion and atrial fibrillation and have a poor prognosis, particularly men >70 years old with higher NYHA class and left atrial dimension >60 mm.

Clinical utility of Doppler echocardiography and tissue Doppler imaging in the estimation of left ventricular filling pressures: A comparative simultaneous Doppler-catheterization study.

BACKGROUND: Noninvasive assessment of diastolic filling by Doppler echocardiography provides important information about left ventricular (LV) status in selected subsets of patients. This study was designed to assess whether mitral annular velocities as assessed by tissue Doppler imaging are associated with invasive measures of diastolic LV performance and whether additional information is gained over traditional Doppler variables. METHODS AND RESULTS: One hundred consecutive patients referred for cardiac catheterization underwent simultaneous Doppler interrogation. Invasive measurements of LV pressures were obtained with micromanometer-tipped catheters, and the mean LV diastolic pressure (M-LVDP) was used as a surrogate for mean left atrial pressure. Doppler signals from the mitral inflow, pulmonary venous inflow, and TDI of the mitral annulus were obtained. Isolated parameters of transmitral flow correlated with M-LVDP only when ejection fraction <50%. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E') showed a better correlation with M-LVDP than did other Doppler variables for all levels of systolic function. E/E' <8 accurately predicted normal M-LVDP, and E/E' >15 identified increased M-LVDP. Wide variability was present in those with E/E' of 8 to 15. A subset of those patients with E/E' 8 to 15 could be further defined by use of other Doppler data. CONCLUSIONS: The combination of tissue Doppler imaging of the mitral annulus and mitral inflow velocity curves provides better estimates of LV filling pressures than other methods (pulmonary vein, preload reduction). However, accurate prediction of filling pressures for an individual patient requires a stepwise approach incorporating all available data.

Severe aortic stenosis with low transvalvular gradient and severe left ventricular dysfunction:result of aortic valve replacement in 52 patients.

BACKGROUND: The outcome of aortic valve replacement in patients with severe aortic stenosis, low transvalvular gradient, and severe left ventricular dysfunction is not well known. METHODS AND RESULTS: Between 1985 and 1995, 52 patients with left ventricular ejection fraction (EF) < or =35% and aortic stenosis with transvalvular mean gradient <30 mm Hg underwent aortic valve replacement. The mean (+/-SD) preoperative characteristics included EF, 26+/-8%; aortic valve mean gradient, 23+/-4 mm Hg; aortic valve area, 0.7+/-0.2 cm(2); and cardiac output, 3.7+/-1.2 L/min. Simultaneous coronary artery bypass graft surgery was performed in 32 patients (62%). Perioperative (30-day) mortality was 21% (11 of 52 patients). Ten additional patients died during follow-up. Advanced age (P=0.048) and small aortic prosthesis size (P=0.03) were significant predictors of hospital mortality by univariate analysis. By multivariate analysis, the only predictor of surgical mortality was smaller prosthesis size. The only predictor of postoperative survival was improvement in postoperative functional class (P=0.04). Postoperative functional improvement occurred in most patients. Postoperative EF was assessed in 93% of survivors; 74% demonstrated improvement. Positive change in EF was related to smaller preoperative aortic valve area and female sex. CONCLUSIONS: Despite severe left ventricular dysfunction, low transvalvular mean gradient, and increased operative mortality, aortic valve replacement was associated with improved functional status. Postoperative survival was related to younger patient age and larger aortic prosthesis size, and medium-term survival was related to improved postoperative functional class.

Annulus paradoxus: transmitral flow velocity to mitral annular velocity ratio is inversely proportional to pulmonary capillary wedge pressure in patients with constrictive pericarditis.

BACKGROUND: The early diastolic velocity of the mitral annulus (E') is reduced in patients with diastolic dysfunction and increased filling pressures. Because transmitral inflow early velocity (E) increases progressively with higher filling pressures, E/E' has been shown to have a strong positive relationship with pulmonary capillary wedge pressure (PCWP) and left ventricular end-diastolic pressure. However, previous studies have primarily involved patients without a pericardial abnormality. In constrictive pericarditis (CP), E' is not reduced, despite increased filling pressures. This study evaluated the relationship between E/E' and PCWP in patients with CP. METHODS AND RESULTS: We studied 10 patients (8 men; mean age, 64+/-7 years) with surgically confirmed CP. Doppler echocardiography was performed to measure early and late diastolic transmitral flow velocities. Tissue Doppler echocardiography was performed to measure E'. PCWP was measured with right heart catheterization. All patients were in sinus rhythm. Mean E and E' were 91+/-15 cm/s and 11+/-4 cm/s, respectively. Mean PCWP was 25+/-6 mm Hg. E' was positively correlated with PCWP (r=0.69, P=0.027). There was a significant inverse correlation between E/E' and PCWP (r=-0.74, P=0.014). Despite high left ventricular filling pressures, E/E' (mean, 9+/-4) was <15 in all but 1 patient. CONCLUSIONS: Paradoxical to the positive correlation between E/E' and PCWP in patients with myocardial disease, an inverse relationship was found in patients with CP.

Human aortic valve calcification is associated with an osteoblast phenotype.

BACKGROUND: Calcific aortic stenosis is the third most common cardiovascular disease in the United States. We hypothesized that the mechanism for aortic valve calcification is similar to skeletal bone formation and that this process is mediated by an osteoblast-like phenotype. METHODS AND RESULTS: To test this hypothesis, we examined calcified human aortic valves replaced at surgery (n=22) and normal human valves (n=20) removed at time of cardiac transplantation. Contact microradiography and micro-computerized tomography were used to assess the 2-dimensional and 3-dimensional extent of mineralization. Mineralization borders were identified with von Kossa and Goldner's stains. Electron microscopy and energy-dispersive spectroscopy were performed for identification of bone ultrastructure and CaPO4 composition. To analyze for the osteoblast and bone markers, reverse transcriptase-polymerase chain reaction was performed on calcified versus normal human valves for osteopontin, bone sialoprotein, osteocalcin, alkaline phosphatase, and the osteoblast-specific transcription factor Cbfa1. Microradiography and micro-computerized tomography confirmed the presence of calcification in the valve. Special stains for hydroxyapatite and CaPO4 were positive in calcification margins. Electron microscopy identified mineralization, whereas energy-dispersive spectroscopy confirmed the presence of elemental CaPO4. Reverse transcriptase-polymerase chain reaction revealed increased mRNA levels of osteopontin, bone sialoprotein, osteocalcin, and Cbfa1 in the calcified valves. There was no change in alkaline phosphatase mRNA level but an increase in the protein expression in the diseased valves. CONCLUSIONS: These findings support the concept that aortic valve calcification is not a random degenerative process but an active regulated process associated with an osteoblast-like phenotype.

Constrictive pericarditis in the modern era: evolving clinical spectrum and impact on outcome after pericardiectomy.

BACKGROUND: The clinical spectrum of constrictive pericarditis (CP) has been affected by a change in incidence of etiological factors. We sought to determine the impact of these changes on the outcome of pericardiectomy. METHODS AND RESULTS: The contemporary spectrum of CP in 135 patients (76% male) evaluated at the Mayo Clinic from 1985 to 1995 was compared with that of a historic cohort. Notable trends were an increasing frequency of CP due to cardiac surgery and mediastinal radiation and presentation in older patients (median age, 61 versus 45 years). Perioperative mortality decreased (6% versus 14%, P = 0.011), but late survival was inferior to that of an age- and sex-matched US population (57+/-8% at 10 years). The long-term outcome was predicted independently by 3 variables in stepwise logistic regression analyses: (1) age, (2) NYHA class, and most powerfully, (3) a postradiation cause. Of 90 late survivors in whom functional class could be determined, functional status had improved markedly (2.6+/-0.7 at baseline versus 1.5+/-0.8 at latest follow-up [P<0.0001]), with 83% being free of clinical symptoms. CONCLUSIONS: The evolving profile of CP, with increasingly older patients and those with radiation-induced disease in the past decade, significantly affects postoperative prognosis. Long-term results of pericardiectomy are disappointing for some patient groups, especially those with radiation-induced CP. By contrast, surgery alleviates or improves symptoms in the majority of late survivors.

Mortality and morbidity of aortic regurgitation in clinical practice. A long-term follow-up study.

BACKGROUND: The outcome of aortic regurgitation conservatively followed in clinical practice is poorly defined. METHODS AND RESULTS: Long-term outcome of 246 patients with severe or moderately severe aortic regurgitation diagnosed by color Doppler echocardiography was analyzed. With conservative management, mortality rate was higher than expected (at 10 years, 34+/-5%, P<0. 001) and morbidity was high (10-year rates of 47+/-6% for heart failure and 62+/-4% for aortic valve surgery). At 10 years, 75+/-3% of patients had died or had surgery and 83+/-3% had had cardiovascular events. In multivariate analysis, predictors of survival were age (P<0.001), functional class (P<0.001), comorbidity index (P=0.033), atrial fibrillation (P=0.002), and left ventricular end-systolic diameter corrected for body surface area (P=0.025). Ejection fraction was also an independent predictor of overall survival, including postoperative follow-up of surgically treated patients (P<0.001). High risk during conservative treatment, with mortality rate in excess of that expected, was noted among patients with severe, even transient, symptoms (24.6% yearly, P<0.001) but also in those with mild (class II) symptoms (6.3% yearly, P=0.02) and in asymptomatic patients with left ventricular ejection fraction <55% (5.8% yearly, P=0.03) or with end-systolic diameter normalized to body surface area >/=25 mm/m2 (7.8% yearly, P=0.004). Surgery performed during follow-up was independently associated with reduced cardiovascular mortality (adjusted hazard ratio, 0.54; P=0.048). CONCLUSIONS: Patients diagnosed with severe aortic regurgitation in clinical practice incur excess mortality and high morbidity, underscoring the serious prognosis of the disease. Surgery, which reduces cardiac mortality rates, should be considered promptly in high-risk patients.

Determination of left-sided pressure gradients by utilizing Doppler aortic and mitral regurgitant signals: validation by simultaneous dual catheter and Doppler studies.

Continuous wave Doppler echocardiography is an accurate and reproducible method for determination of intracardiac pressure gradients in stenotic valve lesions and right-sided regurgitant lesions. Twenty-three patients with either mitral or aortic regurgitation underwent simultaneous continuous wave Doppler and dual catheter pressure recordings to determine if instantaneous pressure gradients can be accurately determined by Doppler ultrasound in left-sided regurgitant valve lesions. Using the modified Bernoulli equation, the maximal and mean pressure gradients between the left ventricle and left atrium were determined by continuous wave Doppler ultrasound in patients with mitral regurgitation and compared with simultaneous catheter-derived pressures. The mean and end-diastolic pressure gradients between the aorta and left ventricle were determined by continuous wave Doppler ultrasound in patients with aortic regurgitation and compared with simultaneous catheter-derived pressures. Diastolic half-times by both continuous wave Doppler ultrasound and catheter pressures were compared in patients with aortic regurgitation. There was a linear correlation between the mean gradients in all patients (r = 0.94; SEE = 6 mm Hg) with a similar correlation between the instantaneous gradients (r = 0.98; SEE = 8 mm Hg). There was a linear correlation between diastolic half-times by catheter and Doppler ultrasound (r = 0.95; SEE = 39 ms). As with other valvular lesions, continuous wave Doppler echocardiography can be used in patients with mitral or aortic regurgitation to accurately determine intracardiac pressure gradients.

Evaluation of diastolic filling of left ventricle in health and disease: Doppler echocardiography is the clinician's Rosetta Stone.

Abnormalities of diastolic function have a major role in producing the signs and symptoms of heart failure. However, diastolic function of the heart is a complex sequence of multiple interrelated events, and it has been difficult to understand, diagnose and treat the various abnormalities of diastolic filling that occur in patients with heart disease. Recently, Doppler echocardiography has been used to examine the different diastolic filling patterns of the left ventricle in health and disease, but confusion about diagnosis and treatment options has arisen because of the misinterpretation of these flow velocity curves. This review presents a simplified approach to understanding the process of diastolic filling of the left ventricle and interpreting the Doppler flow velocity curves as they relate to this process. It has been hypothesized that transmitral flow velocity curves show a progression over time with diseases involving the myocardium. This concept can be applied clinically to estimate left ventricular filling pressures and to predict prognosis in selected groups of patients. Specific therapy for diastolic dysfunction based on Doppler flow velocity curves is discussed.

Diagnosis of lipomatous hypertrophy of the atrial septum by two-dimensional echocardiography.

Originally described in 1964, lipomatous hypertrophy of the atrial septum currently remains a diagnosis established primarily at autopsy. Clinical interest in this disorder has centered on the reported association with supraventricular arrhythmias and sudden death. Because two-dimensional echocardiography allows detailed assessment of atrial septal configuration, we reviewed two-dimensional echocardiographic reports obtained over a 1 year period and identified 17 patients who had features consistent with lipomatous hypertrophy of the atrial septum. Nine were men and the average age was 70 years. Autopsy confirmation of the echographic findings was possible in one patient. In nine patients, ideal body weight was exceeded by 10% or more. The atrial septum viewed from the subcostal transducer position showed a distinctive echo-dense globular thickening sparing the valve of the fossa ovalis. The resultant tomographic image of the atrial septum had a characteristic dumbbell appearance. The mean thickness of the atrial septum was 21 mm (range 15 to 29). Seven patients had supraventricular arrhythmias, and eight had P wave abnormalities. The two-dimensional echocardiographic features described are distinctive and suggest that this technique is the procedure of choice not only for establishing the diagnosis of lipomatous hypertrophy of the atrial septum but also for providing a means for prospective follow-up of patients with this little known entity.

Diaphragmatic hernia mimicking an atrial mass: a two-dimensional echocardiographic pitfall.

Two-dimensional echocardiography has become the diagnostic method of choice for identifying intracardiac masses. However, adjacent extracardiac structures may closely mimic intracardiac masses on the two-dimensional echocardiogram. Five cases of a previously unrecognized phenomenon in which a diaphragmatic hernia mimicked an intraatrial mass are reported. Techniques to identify a diaphragmatic hernia properly on two-dimensional echocardiographic examination and distinguish it from intracardiac masses are discussed.

Frequency and location of prominent left ventricular trabeculations at autopsy in 474 normal human hearts: implications for evaluation of mural thrombi by two-dimensional echocardiography.

The frequency and location of prominent left ventricular trabeculations were studied in 474 autopsy specimens from subjects evenly distributed by sex and age. These structures were observed in 323 (68%) of the hearts, and their frequency was similar in male (72%) and female (65%) subjects. Neither the frequency nor the location varied appreciably with age. Among the 323 hearts with prominent left ventricular trabeculations, 172 (53%) exhibited 2 or more; thus, the total number of trabeculations was 582. Of these 582 trabeculations, 493 (85%) were septoparietal bundles that inserted into both the free wall and the septum. Trabeculations also were observed between two points on the ventricular septum in 37 (6%) of the hearts and between two points along the free wall in 36 (6%). Less common patterns included trabeculations between the ventricular septum and the posteromedial papillary muscle in 10 hearts (2%), the ventricular septum and the anterolateral papillary muscle in 2, the free wall and the posteromedial papillary muscle in 2, the two papillary muscles in 1 and the apex and the ventricular septum in 1. Accordingly, prominent left ventricular trabeculations are considered to be common variants of the normal human heart. Their size, shape and location may lead to their being misinterpreted, possibly as mural thrombi, by two-dimensional echocardiography.

Functional assessment of the Fontan operation: combined M-mode, two-dimensional and Doppler echocardiographic studies.

Combined M-mode, two-dimensional and Doppler echocardiographic studies were used to assess the postoperative status of 33 patients who had undergone the modified Fontan procedure. Twenty-four patients had surgical repair with use of a simple direct right atrium to pulmonary artery anastomosis. The remaining patients had repair with use of a prosthesis or associated Glenn shunt. Twenty-seven patients were studied early in the postoperative period (2 months or less) and the remaining patients were studied up to 6 years postoperatively. A total of 36 examinations were performed. Of the 33 patients, 13 had tricuspid atresia, 12 had double inlet left ventricle with hypoplastic right ventricular outlet chamber and 8 had complex lesions with atrioventricular canal, double outlet right ventricle or a hypoplastic ventricle. Postoperative assessment by M-mode and two-dimensional echocardiography demonstrated normal or mildly reduced ventricular function (ejection fraction greater than 40%) in 22 patients. In 24 patients, a "normal" flow pattern was observed in the pulmonary artery by pulsed Doppler echocardiography, with predominant diastolic flow and accentuation by atrial systole somewhat similar to the venous flow pattern observed in the superior vena cava. "Abnormal" flow patterns (disorganized systolic flow, absence of atrial waves and little or no increase with inspiration) were observed in nine patients with reduced ventricular function or residual shunt. Continuous wave Doppler study also demonstrated mild dynamic subaortic obstruction in two patients. Combined pulsed and continuous wave studies showed atrioventricular valve insufficiency in 10 patients. Follow-up studies revealed a satisfactory clinical course in most patients. Three patients died approximately 4 to 8 months after their Fontan operation.

Incidence and distribution of left ventricular false tendons: an autopsy study of 483 normal human hearts.

The incidence and distribution of left ventricular false tendons were studied in a series of 483 autopsy specimens of human hearts from subjects evenly distributed by sex and age. False tendons were observed in 265 specimens (55%), and their incidence was greater in hearts from male than from female subjects (61 versus 49%; p less than 0.01). Neither the incidence nor the location of false tendons varied appreciably with age. Of the 265 specimens containing false tendons, 100 (38%) exhibited 2 or more, such that the total number of false tendons identified was 414. Of these 414, 272 (66%) were located between the posteromedial papillary muscle and the ventricular septum, 49 (12%) between the two papillary muscles, 47 (11%) between the anterolateral papillary muscle and the ventricular septum, 38 (9%) between the free wall and the septum and 3 (less than 1%) between two aspects of the free wall; 5 (1%) had three or more points of insertion and formed weblike structures. False tendons are common anatomic variants of the normal human left ventricle which may be detected by two-dimensional echocardiography and should not be misinterpreted as pathologic structures such as flail mitral chordae tendineae or mural thrombi.

Ultrasonic aortic valve decalcification: serial Doppler echocardiographic follow-up.

Serial two-dimensional and Doppler echocardiography was performed on 61 patients who had surgical ultrasonic aortic valve decalcification for calcific aortic stenosis. The mean patient age at the time of operation was 77.4 +/- 7.0 years; 93% had moderate to severe preoperative symptomatic limitation. Compared with preoperative studies, Doppler echocardiographic evaluation before hospital discharge revealed a significant reduction in the mean aortic valve pressure gradient (45.3 +/- 16.2 to 14.4 +/- 6.5 mm Hg, p less than 0.0001) and improvement in aortic valve area (0.62 +/- 0.17 to 1.33 +/- 0.33 cm2, p less than 0.0001). There was no initial change in aortic regurgitation grade. Follow-up Doppler echocardiographic evaluation was possible in 43 patients alive at 9.3 +/- 3.9 months. A small but statistically significant trend toward aortic restenosis was found; only one patient had severe restenosis. Severe aortic regurgitation had developed in 26% of patients and moderate aortic regurgitation in 37%. Aortic valve replacement was performed in six patients (14%) with severe symptomatic aortic regurgitation. Significant deficiency in central coaptation as a result of cusp scarification and retraction appeared to be the mechanism of postdecalcification regurgitation. Attempted salvage of the native aortic valve in severe calcific stenosis by ultrasonic decalcification adequately relieves stenosis but leads to an unacceptable incidence of significant aortic regurgitation at follow-up study.

Mechanism of hemodynamic improvement by dual-chamber pacing for severe left ventricular dysfunction: an acute Doppler and catheterization hemodynamic study.

OBJECTIVES: This study was undertaken to determine the mechanism by which improvement in hemodynamic variables may occur with dual-chamber pacing in patients with severe left ventricular dysfunction. BACKGROUND: Dual-chamber pacing has recently been proposed as a therapeutic alternative for the relief of symptoms in patients with dilated cardiomyopathy. METHODS: Fifteen patients with severe left ventricular systolic dysfunction were studied acutely during atrioventricular (AV) sequential pacing at various AV intervals (60, 100, 120, 140, 180 and 240 ms) with use of combined Doppler velocity curves and pressures obtained by high fidelity manometer-tipped catheters and thermodilution cardiac output. RESULTS: Neither cardiac output nor mean left atrial pressure was significantly different when hemodynamic variables in the baseline state were compared with those during AV sequential pacing at the various AV intervals in all patients. The patients were classified into two groups. In group I (eight patients with PR intervals > 200 ms on the rest 12-lead electrocardiogram), cardiac output was significantly increased when AV sequential pacing at the optimal AV interval to output was compared with that at the baseline state (3.0 +/- 1.0 vs. 3.9 +/- 0.43 liters/min, p = 0.005) because timing of mechanical atrial and ventricular synchrony was optimized. In addition, left ventricular end-diastolic pressure and duration of diastolic filling were increased, and diastolic mitral regurgitation was abolished. In group II (seven patients who had normal AV conduction at rest), cardiac output during AV pacing decreased from the baseline value without change in the diastolic filling period. CONCLUSIONS: Dual-chamber pacing may improve acute hemodynamic variables in selected patients with dilated cardiomyopathy, mainly by optimization of the timing of mechanical atrial and ventricular synchrony. Reestablishment of the optimal diastolic filling period and abolition of diastolic mitral regurgitation may also contribute to hemodynamic improvement.