Combined flow-based imaging assessment of optimal cardiac resynchronization therapy pacing vector: a case report.

BACKGROUND: There are still many pendent issues about the effective evaluation of cardiac resynchronization therapy impact on functional mitral regurgitation. In order to reduce the intrinsic difficulties of quantification of functional mitral regurgitation itself, an automatic quantification of real-time three-dimensional full-volume color Doppler transthoracic echocardiography was proposed as a new, rapid, and accurate method for the assessment of functional mitral regurgitation severity. Recent studies suggested that images of left ventricle flow by echo-particle imaging velocimetry could be a useful marker of synchrony. Echo-particle imaging velocimetry has shown that regional anomalies of synchrony/synergy of the left ventricle are related to the alteration, reduction, or suppression of the physiological intracavitary pressure gradients. We describe a case in which the two technologies are used in combination during acute echocardiographic optimization of left pacing vector in a 63-year-old man, Caucasian, who showed worsening heart failure symptoms a few days after an implant, and the effect of the device's optimization at 6-month follow-up. DISCUSSION: The degree of realignment of hemodynamic forces, with quantitative analysis of the orientation of blood flow momentum (φ), can represent improvement of fluid dynamics synchrony of the left ventricle, and explain, with a new deterministic parameter, the effects of cardiac resynchronization therapy on functional mitral regurgitation. Real-time three-dimensional color flow Doppler quantification is feasible and accurate for measurement of mitral inflow, left ventricular outflow stroke volumes, and functional mitral regurgitation severity. CONCLUSION: This clinical case offers an innovative and accurate approach for acute echocardiographic optimization of left pacing vector. It shows clinical utility of combined three-dimensional full-volume color Doppler transthoracic echocardiography/echo-particle imaging velocimetry assessment to increase response to cardiac resynchronization therapy, in terms of reduction of functional mitral regurgitation, improving fluid dynamics synchrony of the left ventricle.

Hypovitaminosis D: comparison between patients with hip fracture and patients with vertebral fractures.

This study analyses the difference in 25OH-vitamin D values between two groups of patients both affected by severe osteoporosis with fragility fractures, but one group has vertebral fractures and the other one has hip fractures. Patients with hip fractures have vitamin D values lower than patients with vertebral fractures. INTRODUCTION: The purpose of this study was to evaluate 25OHD levels in patients with fragility vertebral fractures (VF) and hip fractures (HF) and make a comparison between the groups. METHODS: In the first group were enrolled ambulatory patients with 3 or more moderate to severe VF; in the second group were enrolled patients hospitalized in the Department of Orthogeriatrics undergoing surgery for HF. For all patients, we collected values of 25OHD and PTH. The group of patients with VF was further subdivided into pre-existing VF or recent VF treated within 30 days with vertebroplasty. RESULTS: The sample consists of 180 subjects divided into two groups: 90 with VF and 90 with HF. The average value of 25OHD in the total sample was 13.2 ± 9.6 ng/ml, Vitamin D was significantly lower in the HF group than the VF group (p < 0.001)(VF 18.6 ± 9.7 ng/ml, HF 7.9 ± 5.7 ng/ml). The mean PTH value in the total sample was 67.5 ± 54.9 pg/ml and PTH was significantly higher in the HF group compared to the group with VF (p < 0.001) (VF 55.6 ± 27.2 pg/ml, HF 78.7 ± 70.2 pg/ml). The mean 25OHD value in the recent VF group is 16.0 ± 6.6 ng/ml while in the pre-existing VF group is 19.5 ± 10.4 ng/ml with a statistically significant difference (p < 0.001). CONCLUSIONS: Patients of the same age with severe osteoporosis have a lower 25OHD value when the fracture occur at the hip and is recent, probably this is due to the inflammation caused by fracture and/or surgical intervention.

Atrial reservoir function by strain rate imaging in asymptomatic mitral stenosis: prognostic value at 3 year follow-up.

AIMS: Assessment of left and right systolic atrial reservoir function in asymptomatic mitral stenosis (MS) by strain and strain rate imaging (SRI) and their prognostic power at 3 year follow-up was the purpose of this study. There is clear indication to treat (by surgery or percutaneous valvotomy) symptomatic patients with MS, whereas for the asymptomatic ones, the question is much debated. So, we need new echocardiographic parameters helpful for the management of asymtomatic patients. Atrial reservoir function by SRI could help in evaluation of these patients. METHODS AND RESULTS: Fifty-three asymptomatic patients with MS and 53 healthy controls were evaluated by the standard echo-Doppler study [mitral valve (MV) area, mean gradient, systolic pulmonary pressure, left atrial (LA) width, LA volumes, LA compliance index] and by Doppler myocardial imaging (velocity, strain, and SR of both atria). The endpoint at 3 year follow-up was symptoms, hospitalization for cardiac cause, atrial fibrillation, thrombo-embolic events, valvular surgery, or percutaneous commissurotomy. LA width, volumes, and systolic pulmonary pressure were significantly increased in MS patients (P < 0.001). Atrial myocardial velocities and deformation indices were significantly compromised in MS patients (P < 0.0001). Significant correlation was found between atrial myocardial velocity and MV area (by pressure half-time method: P = 0.019, R = 0.41; by planimetric method: P = 0.016, R = 0.43). Peak systolic LA myocardial strain and SR were significantly correlated with atrial volumes (strain: P = 0.03, R = -0.28; SR: P = 0.0008, R = -0.42), with atrial compliance index (strain: P = 0.04, R = 0.26; SR: P = 0.04, R = 0.16), with atrial ejection fraction (strain: P < 0.0001, R = 0.56; SR: P = 0.03, R = 0.43). At 3 year follow-up, 22 (41%) patients had events. Comparing the MS patients who had events during the 3 year follow-up with those who did not, the former had bigger LA volumes, although these parameters did not reached a significant value, whereas atrial myocardial systolic SR was significantly impaired in patients with events. In multivariate analysis, the best predictor of adverse events was LA peak systolic SR average (P = 0.04; coefficient: 0.113; SE: 0.055; cut-off value of 1.69 s(-1) for LA peak systolic SR average) with a sensitivity of 88%, specificity of 80.6%, area under the receiver operating characteristic curve of 0.852 (SE: 0.048; 95% CI: 0.74-0.93, P = 0.0001). CONCLUSION: Atrial myocardial deformation properties, assessed by SRI, are abnormal in asymptomatic patients with rheumatic MS. The degree of this impairment is predictor of events in a 3 year follow-up. SRI could be helpful in decision-making of asymtomatic patients with MS.

Left atrial myocardial function in either physiological or pathological left ventricular hypertrophy: a two-dimensional speckle strain study.

BACKGROUND: Atrial function is an integral part of cardiac function that is often neglected. The presence of left ventricule hypertrophy (LVH) due to arterial hypertension may impair atrial function. However, it has also been suggested that physical training attenuates the age-associated impairment of diastolic filling. This study investigated whether mechanical dysfunction in the left atrium (LA) is present in patients with either physiological or pathological LVH, using two-dimensional strain rate imaging (2D strain echocardiography; 2DSE). METHODS: Standard echocardiography, exercise stress echo and 2DSE of the left atrium were performed in 40 patients with arterial hypertension, 45 age-matched elite athletes (>40 years) and 25 healthy sedentary controls. Atrial longitudinal strain was performed from the apical views for the basal segments of the LA septum, lateral wall and roof. RESULTS: LV mass index and ejection fraction were comparable between patients with either physiological or pathological LVH. Elite athletes showed increased LV end-diastolic diameter, end-diastolic volume and stroke volume, whereas circumferential end-systolic stress was higher in patients with hypertension. LA diameter and maximum volume were increased but similar between the two groups of patients with LVH. LA active emptying volume and fraction were both higher in patients with hypertension. Conversely, peak systolic myocardial atrial strain was significantly reduced in patients with pathological LVH compared with controls and athletes for all the analysed atrial segments (p<0.0001). Using multivariate analysis, LV end-diastolic volume/body surface area (BSA) (beta coefficient 0.52; p<0.0001) and LV mass (beta = 0.48; p<0.001) in athletes emerged as the only independent determinants of LA lateral wall peak systolic strain. In contrast, in patients with hypertension, an independent negative association of LA lateral wall peak systolic strain with both LV mass (beta = -0.42; p<0.001) and circumferential end-systolic stress (beta = -0.43; p<0.001) was found. In addition, in the overall population of patients with LVH, LA lateral wall systolic strain (beta = 0.49; p<0.0001) was a powerful independent predictor of maximum workload during exercise testing. CONCLUSIONS: 2DSE represents a promising, non-invasive, simple and reproducible technique to assess LA myocardial function in patients with either physiological or pathological LVH. LA myocardial deformation is impaired in patients with hypertension compared with age-matched sedentary controls and elite athletes, and is closely associated with functional capacity during effort.

WITHDRAWN: Prognostic Value of Pharmacologic Stress Echocardiography in Diabetic Patients.

The publisher regrets that this was an accidental duplication of an article that has already been published in Eur. J. Echocardiogr., 4 (2003) 202-208, . The duplicate article has therefore been withdrawn.

Prognostic value of intra-left ventricular electromechanical asynchrony in patients with mild hypertrophic cardiomyopathy compared with power athletes.

OBJECTIVES: We sought to assess the indexes of myocardial activation delay, using Doppler myocardial imaging (DMI), as potential diagnostic tools and predictors of cardiac events in patients with hypertrophic cardiomyopathy (HCM) compared with power athletes. BACKGROUND: the distribution and magnitude of left ventricular (LV) hypertrophy are not uniform in patients with HCM, which results in heterogeneity of regional LV systolic function. METHODS: The study population comprised 70 young patients with HCM (mean (SD) age 29.4 (5.9) years) with mild septal hypertrophy (15-19 mm) and 85 age and sex matched athletes with septal thickness >12 mm, followed up for 44.4 (10.8) months. Using pulsed DMI, myocardial peak velocities, systolic time intervals, and myocardial intraventricular and interventricular systolic delays were measured in six different basal myocardial segments. RESULTS: DMI analysis showed in HCM lower myocardial both systolic and early diastolic peak velocities of all the segments. Patients with HCM also showed significant interventricular and intraventricular delay (p<0.0001), whereas athletes showed homogeneous systolic activation of the ventricular walls. During the follow up, seven sudden deaths occurred in the HCM group, while no cardiovascular event was observed in the group of athletes. In patients with HCM, intraventricular delay on DMI was the most powerful independent predictor of sudden cardiac death (p<0.0001). An intraventricular delay >45 ms identified with high sensitivity and specificity patients with HCM at higher risk of ventricular tachycardia and cardiac events (test accuracy 90.6%). CONCLUSIONS: DMI may be a valid supporting tool for the differential diagnosis between HCM and "athlete's heart". In patients with HCM, DMI indexes of intraventricular delay may provide additional information for selecting subgroups of patients with HCM at increased risk of ventricular arrhythmias and sudden cardiac death at follow up. Accordingly, such patients may benefit from early intensive treatment and survey. MINIABSTRACT: Doppler myocardial imaging may represent a valid supporting tool for the differential diagnosis between mild hypertrophic cardiomyopathy (HCM) and "athlete's heart". In patients with HCM, DMI indexes of intraventricular delay may provide additional information for selecting subgroups of patients with HCM at increased risk of ventricular arrhythmias and sudden cardiac death at follow up.

Association between intraventricular myocardial systolic dyssynchrony and ventricular arrhythmias in patients with hypertrophic cardiomyopathy.

BACKGROUND: The distribution and magnitude of left ventricular (LV) hypertrophy are not uniform in patients with hypertrophic cardiomyopathy (HCM), which results in regional heterogeneity of LV systolic and diastolic function. The aim of the study was to evaluate LV regional systolic asynchrony in patients with HCM by pulsed Doppler myocardial imaging (DMI). METHODS: We studied 35 HCM patients and 45 age- and sex-matched controls. By the use of DMI, the following five different basal myocardial segments were measured: systolic peak velocity (Sm); early- and late-diastolic peak velocities; pre-contraction time (Q-Sm) (from the beginning of Q-wave of ECG to the onset of Sm); intraventricular systolic delay (IntraV-Del) (difference of Q-Sm in different LV myocardial segments); interventricular delay (InterV-Del) (difference of Q-Sm between the most delayed LV segment and right ventricular lateral wall). RESULTS: DMI analysis showed in HCM lower myocardial systolic and early-diastolic peak velocities of all the analyzed segments. As for time intervals, controls showed homogeneous systolic activation of the ventricular walls. Conversely, HCM group, despite the absence of intraventricular conduction defects by surface ECG, showed significant both Inter- and IntraV-Del (P < 0.0001). Linear regression models pointed out independent positive associations of IntraV-Del with LV outflow gradient and septal wall thickness in HCM (P < 0.001). An IntraV-Del >30 msec well differentiated controls and HCM. In addition, an IntraV-Del > 45 msec (ROC curve) identified a subgroup of HCM patients with nonsustained ventricular tachycardia during Holter monitoring (90.9% sensitivity and 95.8% specificity). CONCLUSIONS: The impairment of intrarventricular systolic synchronicity is strongly related to increased septal thickness and LV outflow-tract gradient in HCM. DMI analysis may be able to select subgroups of HCM patients at an increased risk of ventricular tachyarrhythmias.

Right ventricular myocardial dysfunction in adult patients late after repair of tetralogy of fallot.

AIM OF THE STUDY: To detect in adult patients late after repair of Tetralogy of Fallot (TOF) possible correlation between myocardial parameters assessed at rest by Tissue Doppler (TD) and cardiac performance during physical effort. METHODS: Doppler echo, treadmill test and pulsed TD of both mitral and tricuspid annulus were performed in 25 healthy subjects and in 40 adult patients who had undergone surgery for TOF at a mean age of 1.4+/-0.5 years. Exclusion criteria were echocardiographic evidence of residual pulmonary, either stenosis or regurgitation. By use of TD, the following parameters were assessed: systolic peak velocities (Sm), pre-contraction time, contraction time, early (E(m)) and late (A(m)) diastolic velocities, E(m)/A(m) ratio, relaxation time. By treadmill test, we measured: maximal heart rate (HR), systolic blood pressure (SBP), rate-pressure product, maximal workload, time duration of the exercise. RESULTS: the two groups were comparable for left ventricular measurements and for all transmitral and transtricuspid Doppler indexes, while tricuspid ring diameter was increased in TOF. TD analysis showed in TOF lower S(m), E(m) and E(m)/A(m) ratio and prolonged PCT(m) and Rt(m) at tricuspid annulus level, despite comparable TD mitral annulus indexes. By treadmill test, TOF showed reduced time of exercise, number of METS reached and rate-pressure product. Multiple linear regression models evidenced in TOF independent positive association between tricuspid Em velocity and time of exercise (p<0.0001), achieved METS at peak effort (p<0.001) and rate-pressure product (p<0.001). An E(m) peak velocity of tricuspid annulus lower than 0.13 m/s showed 90% sensitivity and 93% specificity in identifying TOF patients unable to perform maximal exercise test. CONCLUSIONS: despite normal Doppler parameters, adult patients late after correction of TOF showed impaired right ventricular myocardial function. In these patients pulsed TD may be taken into account as a valuable supporting tool to predict the effort response and possibly to assess long-term follow-up of cardiac functional reserve.

Right ventricular myocardial activation delay in adult patients with right bundle branch block late after repair of Tetralogy of Fallot.

Electromechanical interaction, with prolonged QRS duration due to right ventricular (RV) overload, has been described as a predictor of unfavorable outcome in patients late after correction of Tetralogy of Fallot (TOF). Aim of our study was to evaluate myocardial function and activation delay of both left and right ventricles in TOF patients. Doppler echo, treadmill test and pulsed Tissue Doppler (TD) were performed in 25 healthy subjects and in 30 adult patients who had undergone surgery for TOF, all with right bundle branch block on ECG. Exclusion criteria were evidence of residual pulmonary either stenosis or regurgitation. By use of TD, the level of both LV mitral and RV tricuspid annulus were measured: systolic (Sm), early- and late-diastolic (Em and Am) regional peak velocities. The indexes of myocardial systolic activation were calculated: precontraction time (PCTm) and interventricular activation delay (InterV-del) (difference of PCTm between RV and LV segments). The two groups were comparable for LV diameters and for Doppler indexes, while QRS duration was prolonged and RV end-diastolic diameter was increased in TOF. By TD analysis, only at the level of tricuspid annulus TOF patients had lower Sm and Em, and increased RV PCTm ( p<0.001 ) and InterV-del ( p<0.0001 ), even after adjustment for heart rate (HR) and QRS duration. By treadmill test, TOF showed reduced cardiac functional reserve. In seven patients non-sustained ventricular tachycardia was documented during physical effort. By multivariate analysis, RV Em ( p<0.001 ), and InterV-del ( p<0.01 ) were independently associated to maximal workload at peak effort. The same InterV-del was an independent determinant of risk of ventricular arrhythmias during effort ( p<0.01 ). A cut-off point of Em peak velocity of tricuspid annulus <0.13 m/s at rest showed a sensitivity of 91% and a specificity of 88% in identifying TOF patients with submaximal exercise test. A cut-off point of InterV-del >55 ms showed 87% sensitivity and 88% specificity to detect increased risk of ventricular arrhythmias during effort. In TOF patients, TD analysis at rest may be taken into account as a non-invasive and easy-repeatable tool to predict cardiac performance during physical effort, and to select subgroups of patients at increased risk of ventricular arrhythmias.

Prognostic value of pharmacological stress echocardiography in diabetic patients.

Our study was undertaken to assess the prognostic significance of pharmacological stress echocardiography in 325 diabetic patients. Pharmacological stress echocardiography was performed for diagnosis of coronary artery disease in 128 patients, and for risk stratification in 197 patients. Follow-up was 34 months. Cardiac-related death and non-fatal myocardial infarction were considered hard events. During the follow-up period, there were 38 deaths and 23 acute non-fatal myocardial infarctions. By univariate analysis, a pharmacological stress echocardiography positive response for ischaemia indicated an increased risk of cardiovascular death. However, by multivariate analysis, advanced age and peak ejection fraction <40% were the only independent predictors of cardiac death. The same peak ejection fraction (EF) <40%, rest wall motion score index and previous myocardial infarction were independent predictors of hard events. After dividing the population into two subgroups on the basis of EF at rest, only a peak EF <40% and a pharmacological stress echocardiography positive test were powerful independent predictors of cardiovascular mortality.

Right ventricular diastolic dysfunction in arterial systemic hypertension: analysis by pulsed tissue Doppler.

AIMS: This study analyses right ventricular longitudinal function in arterial systemic hypertension by pulsed tissue Doppler. METHODS AND RESULTS: Thirty normotensives and 30 hypertensives, free of cardiac drugs, underwent standard Doppler echocardiography and pulsed tissue Doppler of right ventricular lateral tricuspid annulus and left ventricular lateral mitral annulus. By tissue Doppler, systolic and diastolic measurements were obtained. Hypertensives had higher left ventricular mass and impaired Doppler diastolic indexes, without changes of global systolic function. Tissue Doppler showed reduction of right ventricular E/A ratio and prolongation of relaxation time in comparison with controls (both P<0.00001). In the overall population, the length of tissue Doppler derived right ventricular relaxation time was positively related to right ventricular anterior wall thickness while right ventricular E/A ratio was positively related to E/A ratio of left ventricular mitral annulus (both P<0.00001). These relations remained significant even after adjusting for clinical and echocardiographic confounders by separate multivariate models. CONCLUSIONS: Arterial systemic hypertension is associated to right ventricular longitudinal diastolic dysfunction. This dysfunction involves the prolongation of active relaxation, which is independently associated with the degree of right ventricular hypertrophy and the impairment of passive wall properties, which is mainly due to ventricular interaction occurring under left ventricular pressure overload conditions.

Usefulness of Doppler tissue imaging for the assessment of right and left ventricular myocardial function in patients with dual-chamber pacing.

The aim of the study was to evaluate by Doppler tissue imaging (DTI) the combined effects of atrio-ventricular (AV) delay and heart rate (HR) changes on global and segmental right (RV) and left (LV) ventricular diastolic function in 15 patients with dual-chamber pacemakers paced in the DDD mode. RV and LV inflow velocities and regional systolic and diastolic pulsed-wave (PW) DTI parameters were analyzed at four different pacing modes: (1) HR 70 beats/min, AV delay 125 ms; (2) HR 70 beats/min, AV delay 188 ms; (3) HR 89 beats/min, AV delay 125 ms; (4) HR 89 beats/min, AV delay 188 ms. For each pacing mode selected, RV diastolic filling velocities always prevailed over LV ones. As for RV and LV adaptation to the four different stimulation protocols, a higher paced rate and a prolonged AV delay caused across both the AV valves a decrease of E wave and of E/A ratios. The intersegmental comparison of PW-DTI parameters outlined that RV free wall exhibited significantly higher peak systolic (Sm) and early-diastolic (Em) wall velocities, and longer systolic ejection time. Considering separately RV and LV segmental physiology at the four programmed pacing modes, an increase in HR determined a progressive shortening of systolic ejection times in all the segments analyzed. Moreover, in each region the Em/Am ratio decreased with higher HR and longer AV delay. Conversely, Em encountered a progressive reduction in RV free wall, while remaining quite unchanged in all the LV regions. Both ventricles shared a similar pattern of global and regional adaptation to programmed HR and AV delay modifications, consisting in a progressive greater contribution of late diastole to ventricular filling at higher HR and more prolonged AV delay. However, at a regional level the right ventricle exhibited higher systolic and diastolic wall velocities than all left ventricular regions.

Association between myocardial right ventricular relaxation time and pulmonary arterial pressure in chronic obstructive lung disease: analysis by pulsed Doppler tissue imaging.

This study assessed right ventricular function in chronic obstructive lung disease and pulmonary hypertension by Doppler tissue imaging. Doppler echocardiography of the right ventricle and Doppler tissue imaging of the tricuspid annulus were performed in 63 subjects: 20 healthy controls, 20 with lung disease, and 23 with both lung disease and pulmonary hypertension. Two-dimensional tricuspid systolic plane excursion was lower in patients with pulmonary hypertension than in the other 2 groups. Doppler tricuspid inflow measurements distinguished patients in both of the diseased groups from the control subjects, but they did not differentiate patients with pulmonary hypertension from those without it. The ratio of peak E-wave to peak A-wave velocities derived by Doppler tissue imaging was significantly lower and the myocardial acceleration time longer in both groups of lung disease than in the control group. Only myocardial relaxation time distinguished the 3 groups (all P <.01); a gradual increase in time occurred, with the shortest time seen in controls, a longer time in patients with chronic obstructive lung disease without pulmonary hypertension, and the longest time in patients with lung disease and pulmonary hypertension. In the overall population including subjects with at least minimal tricuspid regurgitation, myocardial relaxation time was positively related to pulmonary systolic pressure. In conclusion, Doppler tissue imaging distinguishes subsets of patients affected by lung disease with or without pulmonary hypertension and identifies patients with different levels of pulmonary artery systolic pressure.

Impact of myocardial diastolic dysfunction on coronary flow reserve in hypertensive patients with left ventricular hypertrophy.

BACKGROUND: The aim of the study was to assess the possible association, in hypertensive patients, between left ventricular myocardial diastolic dysfunction and coronary flow reserve (CFR) in relation to the presence of left ventricular hypertrophy (LVH). METHODS: Twenty-eight untreated hypertensives (22 males, 6 females, mean age 53.1 years), free of coronary artery disease, were enrolled in the study. Standard Doppler echocardiography, color Doppler tissue imaging of the posterior septum during dobutamine stress and second harmonic Doppler of the distal left anterior descending coronary vessel, at baseline and after maximal hyperemia induced by dipyridamole, were performed. CFR was estimated as the ratio between hyperemic and baseline diastolic velocities. Hypertensives were divided into two groups according to the left ventricular mass index: 15 without LVH (left ventricular mass index < 51 g/m2.7) and 13 with LVH (left ventricular mass index > 51 g/m2.7). The two groups were comparable for sex prevalence, age, body mass index, baseline heart rate and blood pressure. RESULTS: Color Doppler tissue imaging did not show any significant difference of both the baseline and high-dobutamine septal systolic peak velocities between the two groups. The ratio between myocardial early and atrial peak velocities (Em/Am ratio) was lower in patients with LVH, either at baseline (p < 0.01) or at high-dose dobutamine (p < 0.0001). Also, CFR was lower in the presence of LVH (p < 0.01). After adjusting for age, body mass index, left ventricular mass index, diastolic blood pressure and high-dose dobutamine heart rate by a multiple linear regression analysis, the high-dose dobutamine Em/Am ratio was an independent contributor of CFR in the overall hypertensive population (beta = 0.65, p < 0.0001) (cumulative r2 = 0.38, p < 0.0001). CONCLUSIONS: The combined use of second harmonic Doppler and color Doppler tissue imaging identifies, in arterial hypertension, an association between myocardial diastolic properties and CFR, independent of the presence of LVH. In hypertensive patients free of coronary artery stenosis, left ventricular myocardial diastolic dysfunction may be a determinant in the impairment of the coronary microvessel vasodilation capacity or a marker of silent ischemia involving the microvascular circulation.

Risk predictors of paroxysmal atrial fibrillation following aortic valve replacement.

BACKGROUND: Atrial fibrillation (AF) is the most frequently encountered arrhythmic complication associated with cardiac surgery. The aim of this paper was to identify the clinical predictors of AF occurrence following aortic valve replacement. METHODS: Three hundred and two patients were included in this study and divided into two groups according to the absence (SR group, 243 patients, mean age 55.6 +/- 15 years) or the evidence (AF group, 59 patients, mean age 63.8 +/- 11 years) of post-aortic valve replacement AF. Sixty-five perioperative variables (37 preoperative, 8 intraoperative and 20 postoperative) were considered. RESULTS: Post-aortic valve replacement paroxysmal AF occurred in 59 out of 302 patients (19%). At univariate analysis, post-aortic valve replacement AF was associated with advanced age, left atrial enlargement, preoperative episodes of paroxysmal AF, the use of a warm blood cardioplegic solution and normothermia, administration of inotropic agents, prolonged assisted ventilation but also with postoperative acidosis, electrolyte imbalance and atrioventricular and intraventricular conduction disorders. Stepwise forward multivariate logistic regression analysis identified age (p = 0.002, odds ratio--OR 1.04), left atrial enlargement (p = 0.004, OR 2.6), a prior history of paroxysmal AF (p = 0.0003, OR 10.9), and postoperative electrolyte imbalance (p = 0.01, OR 2.3) as independent correlates of AF, whereas the use of hypothermia appeared to be a protective factor (p = 0.0004, OR 0.26). CONCLUSIONS: According to our findings, post-aortic valve replacement AF seems to be associated with well-defined anatomical and electrical substrates generated by advanced age, increased left atrial dimensions, and a possible electrical remodeling consequent to prior repetitive episodes of paroxysmal AF. On these grounds, external factors such as postoperative electrolyte imbalance might enhance atrial ectopic activity and trigger postoperative sustained tachyarrhythmias, while the use of hypothermia might allow for better protection of the atrial myocardium against intraoperative ischemia.

The prognostic value of myocardial viability recognized by low dose dipyridamole echocardiography in patients with chronic ischaemic left ventricular dysfunction.

AIMS: The aim of this study was to assess the prognostic value of myocardial viability recognized as a contractile response to vasodilator stimulation in patients with left ventricular dysfunction in a large scale, prospective, multicentre, observational study. METHODS AND RESULTS: Three hundred and seven patients (mean age 60 +/- 10 years) with angiographically proven coronary artery disease, previous (>3 months) myocardial infarction and severe left ventricular dysfunction (ejection fraction <35%; mean ejection fraction: 28 +/- 7%) were enrolled in the study. Each patient underwent low dose dipyridamole echo (0.28 mg x kg(-1) in 4 min). Myocardial viability was identified as an improvement of >0.20 in the wall motion score index. By selection, all patients were followed up for a median of 36 months. One-hundred and twenty-four were revascularized either by coronary artery bypass grafting (n=83) or coronary angioplasty (n=41). The only end-point analysed was cardiac death. In the revascularized group, cardiac death occurred in one of the 41 patients with and in 16 of the 83 patients without a viable myocardium (2.4% vs 19.3%, P<0.01). Outcome, as estimated by Kaplan-Meier survival, was better for patients with, compared to patients without, a viable myocardium, who underwent coronary revascularization (97.6 vs 77.4%, P=0.01). Using a Cox proportional hazards model, the presence of myocardial viability was shown to exert a protective effect on survival (chi-square 4.6, hazard ratio 0.1, 95% CI 0.01-0.8, P<0.03). The survival rate in medically treated patients was lower than in revascularized patients irrespective of the presence of a viable myocardium (79.7% vs 86.2, P=ns). CONCLUSION: In severe left ventricular ischaemic dysfunction, myocardial viability, as assessed by low dose dipyridamole echo, is associated with improved survival in revascularized patients.

Long-term prognostic value of dipyridamole and dobutamine stress echocardiography in patients with known or suspected coronary artery disease.

BACKGROUND: Pharmacological stress echocardiography (PSE) is increasingly used for cardiac risk stratification. Our study was undertaken to assess the long-term prognostic significance of PSE in patients with known or suspected coronary artery disease. METHODS: We studied 622 consecutive patients who underwent PSE with either dobutamine or dipyridamole. Outcome was finally assessed in 448 patients for a mean period of 32.9 months. Death and hard events (death and myocardial infarction) were considered as endpoints. RESULTS: PSE was positive for ischemia in 192 patients (42.9%). During the follow-up, 53 hard events occurred, including 28 deaths and 25 acute non-fatal myocardial infarctions. With multivariate analysis, peak ejection fraction < 40% appeared to be the strongest predictor of cardiac-related deaths and of hard endpoints (chi2 28.4 and 32.0, respectively). Peak wall motion score index revealed a strong predictive value of the same events (chi2 8.6 and 16.3, respectively). An ischemic pattern at PSE predicted a 2.4 higher cardiac mortality rate over a 5-year follow-up (9.4 vs 3.9%, p < 0.01; log rank 5.68), while patients with a peak ejection fraction < 40% had a cardiac-related mortality 4 times higher (16.3 vs 4.1%, p < 0.00001; log rank 21.16). Hard events occurred in 6.7% of patients with a negative test vs 18.8% of patients with a positive test (p < 0.001; log rank 15.8), while hard event rate was 8.4% in patients with a peak ejection fraction > 40% vs 27.5% in patients with a peak ejection fraction < 40% (p < 0.00001; log rank 38.64). CONCLUSIONS: The ischemic response to PSE showed a sustained prognostic value for cardiac events, especially in patients considered at either intermediate or high risk on the basis of recognized clinical risk factors. However, only the evaluation of both descriptors of global left ventricular performance and of the extension of induced ischemia may better help to select patients at higher risk of cardiac death.

Doppler tissue imaging.

This paper try to give a general overview of the main areas of DTI clinical application, its main technical limitations, new directions still under investigation and some potential future developments of this emerging imaging technique. In this review article we pretend to discuss the main aspects of the new DTI method, its present "state of the art" and future perspectives of scientific and technical development.

Right ventricular myocardial diastolic dysfunction in different kinds of cardiac hypertrophy: analysis by pulsed Doppler tissue imaging.

BACKGROUND: Right ventricular (RV) chamber involvement has been demonstrated in hypertrophic cardiomyopathy (HCM) as well as in hypertensive left ventricular hypertrophy (LVH) but little is known about RV myocardial dysfunction occurring in these two pathologies. The aim of this study was to compare Doppler tissue imaging (DTI) of the right ventricle in HCM and LVH in relation to DTI of the left ventricle and Doppler standard of the RV and left ventricular (LV) inflow. METHODS: Thirty controls, 20 hypertensives with LVH, and 23 patients with HCM involving the interventricular septum underwent Doppler echocardiography and pulsed DTI of the LV lateral mitral annulus and the RV lateral tricuspid annulus. RESULTS: Patients with HCM had a higher blood pressure, septal thickness and LV mass in comparison with the other two groups. The RV wall thickness did not differ between HCM and LVH. The fractional shortening, but not the tricuspid annular plane excursion, was higher in HCM. After adjusting for the mean blood pressure, the Doppler-derived global LV and RV diastolic functions were more impaired in HCM than in LVH. Also the majority of DTI LV and RV diastolic measurements were altered more in HCM. At the RV tricuspid annulus, myocardial diastolic indexes were impaired in HCM and LVH in comparison with controls but the deceleration and relaxation times distinguished also HCM and LVH, being much longer in HCM (p < 0.0001). In the overall population, the RV myocardial relaxation time was positively related to the septal wall thickness and the RV wall thickness, even after adjusting for age, heart rate, diastolic blood pressure, fractional shortening and DTI mitral relaxation time. CONCLUSIONS: The impairment of RV myocardial relaxation is much more evident in HCM than in LVH, its degree being independently associated with the extent of both the septal and RV wall thickness. Pulsed DTI may be useful to distinguish the extent of RV myocardial dysfunction in different types of cardiac hypertrophy.