Left ventricular geometry and operative mortality in patients undergoing mitral valve replacement.

BACKGROUND: Distortion of left ventricular (LV) shape is often associated with LV dysfunction and is thought to be an independent predictor of survival in patients with coronary disease. HYPOTHESIS: The purpose of this study was to examine the relationship between LV geometry and hospital mortality in patients with mitral regurgitation (MR) undergoing mitral valve surgery. METHODS: A consecutive series of patients (aged 68+/-12 years, 47% men) (n = 149) with MR who underwent cardiac catheterization, left ventriculography, and mitral valve surgery from 1995 to 1996 at Mount Sinai Medical Center was studied. Left ventriculograms, clinical records, and hemodynamics were reviewed. Left ventricular volumes and ejection fraction were calculated using standard techniques. Left ventricular shape in diastole and systole was evaluated using the sphericity index, which is defined as the end-systolic LV volume (x 100) divided by the volume of a sphere whose diameter is equal to the LV long axis. RESULTS: In the patients studied, the etiology of mitral insufficiency was mitral valve prolapse in 40.9%, ischemic heart disease in 40.3%, rheumatic heart disease in 11.4%, and prosthetic valvular dysfunction in 7.4%. The average ejection fraction was 65%+/-17. Systolic sphericity index (SSI) was 36%+/-15 in patients who died, compared with 25%+/-11 in patients who lived (p < 0.001). A multivariate model was constructed using hemodynamic and angiographic indices derived during preoperative cardiac catheterization. Systolic sphericity index (odds ratio = 1.6 for each point increase, p < 0.01) was found to be an independent predictor of postoperative survival in the global population, as well as in patients with coronary disease (p<0.01). CONCLUSION: Left ventricular geometry is an independent angiographic risk factor for survival following mitral valve replacement. Sphericity index is a simple method for assessing LV geometry which should be calculated in patients as part of risk stratification.

Coronary arteriovenous fistula with a giant aneurysm: role of transesophageal echocardiography.

Congenital coronary arteriovenous fistulas are rare anomalies. Patients may present with congestive heart failure, ischemic chest pain, or endocarditis. In this case, transesophageal echocardiography provided valuable additional information to that obtained from cardiac catheterization, which was essential for the diagnosis and planning of surgical correction.

Lymphocytic myocarditis presenting as unexplained ventricular arrhythmias: diagnosis with endomyocardial biopsy and response to immunosuppression.

During a period of 18 months beginning in January 1982, a total of 65 patients were referred to the Miami Heart Institute for evaluation of either aborted out of hospital sudden death, ventricular tachycardia resistant to standard clinically directed antiarrhythmic medication programs or high grade ventricular arrhythmia (Lown class greater than or equal to IV B) with or without syncope. After complete evaluation including cardiac catheterization in all but 1 patient, 17 patients were identified in whom no obvious cardiac disease could be found. Twelve of the 17 underwent right ventricular endomyocardial biopsy. Six of the 12 biopsies demonstrated clinically unsuspected lymphocytic myocarditis (Group A). Findings in three of the remaining six biopsies were consistent with an early cardiomyopathy and in three were completely normal (Group B). Retrospective review of the clinical, laboratory, electrophysiologic, hemodynamic and angiographic data failed to identify a marker that reliably separated Group A from Group B patients. In addition to antiarrhythmic therapy guided by laboratory electrophysiologic study, all Group A patients were treated with prednisone and azathioprine. After 6 months of immunosuppression, all patients with myocarditis were reevaluated in the hospital without antiarrhythmic medication. Ventricular tachycardia/fibrillation could not be provoked in the laboratory during repeat electrophysiologic testing in five of the six patients. Repeat myocardial biopsy after all immunosuppressive therapy had been discontinued revealed absence of inflammation associated with varying degrees of residual interstitial fibrosis. There were no deaths. It was concluded that a patient with an otherwise clinically silent lymphocytic myocarditis can present with potentially life-threatening ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Endomyocardial fibrosis. Preoperative diagnosis and surgical therapy.

The case of a Nigerian student with biventricular endomyocardial fibrosis is presented. Diagnosis was suggested by cardiac catheterization and histologically confirmed by a percutaneous endomyocardial biopsy. Successful surgical repair including mitral valve replacement, tricuspid valve reconstruction, and left ventricular endomyocardial resection was performed through a biatrial approach. The pathologic and surgical considerations are reviewed. This is one of the few cases of endomyocardial fibrosis reported from the United States and the first in which a percutaneous endomyocardial biopsy was used to provide a definitive preoperative histologic diagnosis.

Aneurysmal coronary artery disease.

To examine the clinical and historical features and the natural history of aneurysmal coronary disease, we reviewed the registry data of the Coronary Artery Surgery Study (CASS). Nine hundred seventy-eight patients, representing 4.9% of the total registry population, were identified as having aneurysmal disease. No significant differences were noted between aneurysmal and nonaneurysmal coronary disease patients when features such as hypertension, diabetes, lipid abnormalities, family history, cigarette consumption, incidence of documented myocardial infarction, presence and severity of angina, and presence of peripheral vascular disease were examined. In addition, no difference in 5-year medical survival was noted between these two groups. These findings suggest that aneurysmal coronary disease does not represent a distinct clinical entity but is, rather, a variant of coronary atherosclerosis.

Guidelines for effective and safe percutaneous intraaortic balloon pump insertion and removal.

During the 12 month period beginning February 1980, a total of 54 consecutive patients had 60 attempts at percutaneous insertion of an intraaortic balloon because of medically uncontrollable angina, cardiogenic shock either in the setting of an acute myocardial infarction or within hours of cardiac surgery and as a prophylactic measure in high risk patients before cardiac surgery. The balloon was successfully inserted in 49 patients (91 percent). In five patients the balloon could not be inserted in spite of eight attempts because of tortuosity of the iliac artery. All nine patients in whom balloon insertion was attempted without fluoroscopy had the device inserted successfully. The four insertion attempts during cardiac massage were all successful. Experience with use of the new longer introducer sheath is described. Since its acquisition there has not been a single balloon pump insertion failure in 20 consecutive patients including 6 patients in whom initial attempts through the conventional short death were unsuccessful because of iliac tortuosity. The major complications encountered in the present series were thromboembolic: femoral arterial thrombosis developed in five patients (10.2 percent) and an asymptomatic pulse loss in the contralateral foot developed in another. There were no cases of pseudoaneurysm, groin hematoma, aortic dissection or infection related to the percutaneous balloon. On the basis of this experience, several guidelines are suggested for safe and effective percutaneous insertions and removal of the intraaortic balloon pump.

Safe transthoracic left ventricular puncture performed with echocardiographic guidance.

Retrograde aortic left ventricular pressure recording is difficult to obtain and often unreliable in the presence of a mechanical aortic valve prosthesis. Under echocardiographic guidance, we have safely performed transthoracic left ventricular puncture for pressure recording in seven patients with an aortic valve prosthesis. The transducer is placed at the left sternal border and then slid laterally until the right ventricular cavity and interventricular septal echoes disappear, but before the echoes from the left lung are recorded. The chest wall is marked and the transducer is angled until the mitral valve echoes are identified. The transducer angle and direction are recorded with external markers, and the left ventricular cavity depth is measured. An 18-gauge needle is then inserted the determined depth into the left ventricle, guided exactly by the echocardiographic external markers. The procedure was successful in each patient on the first attempt without a single complication. We conclude that this technique affords the operator greater control when left ventricular pressure must be recorded by transthoracic puncture and that it may reduce the risk of potentially serious complications.

Echocardiographic estimation of aortic-valve gradient in aortic stenosis.

Fifty-five consecutive patients with aortic stenosis underwent echocardiography at the time of cardiac catheterization. Left ventricular systolic pressure was estimated from the echocardiogram assuming that peak systolic circumferential was stress was constant. Systolic blood pressure was substracted from the estimated left ventricular pressure to obtain the aortic-valve gradient. Of 44 patients with adequate echocardiograms and catheterization studies, 30 had their aortic gradient accurately estimated by the echocardiogram (r = 0.75). All 30 patients had normal left ventricular systolic function estimated echocardiographically. The echocardiogram underestimated the aortic gradient in all seven patients with poor left ventricular systolic function. An accurate echocardiographic estimate of aortic-valve gradient can be obtained in patients with normal left ventricular function. The technique can identify those patients with insignificant left ventricular outflow obstruction, thereby obviating the need for invasive studies.

Relation between phasic mitral flow and the echocardiogram of the mitral valve in man.

Ten patients without valvular disease were studied by ventriculography, and the rate and pattern of phasic blood flow into the left ventricle were determined by ventricular volume determinations at intervals of 33 ms during a single diastolic filling period. The derived left ventricular inflow patterns were then compared with the echocardiographic mitral EF slope obtained no more than 25 minutes before left ventriculography. The steepness of the EF slope was found to be inversely correlated with the time required to reach peak inflow velocity (r = 0.80, P less than 0.01) and directly correlated with the peak left ventricular inflow velocity divided by the time required to reach peak velocity (r = 0.72, P less than 0.05). No correlation was found between mean flow velocity into the left ventricle and the EF slope (r = 0.40, P = NS). A significant inverse correlation was found between the EF slope and the fraction of the diastolic filling period elapsed when 50 per cent of the filling volume had entered the left ventricle (r = 0.85, P less than 0.01). These findings suggest that the time required to reach left ventricular peak inflow velocity is one of the determinants of the mitral EF slope.

Interobserver variability in echocardiography.

High-quality echocardiograms were performed on 146 normal individuals whose ages ranged from 3 to 73 years (mean 27 years). Normal values for mitral diastolic excursion and E-F slope, the chamber dimensions of the right ventricle, left atrium, and left ventricle, the aortic root dimension, and thickness of the interventricular septum and left ventricular posterior wall were determined. Each tracing was then read independently by two experienced echocardiographers. The extent of interobserver variability was calculated and expressed as a percent of the mean. The 95 per cent confidence limits for these estimates were calculated. Small but significant interobserver variability was found for all nine of these commonly measured echocardiographic parameters. Observer variability is a small but potentially important consideration in investigative echocardiography.

Echocardiographic spectrum of posterior systolic motion of the mitral valve in the general population.

The prevalence of mitral valve prolapse has been established in selected groups of patients but not in the general population. The present study was designed to define the echocardiographic spectrum of mitral valve motion in a population of young individuals without clinical evidence of significant cardiac disease or hypertension. Echocardiograms were performed on 136 normal volunteers. Six subjects (4.4 per cent) had mitral valve prolapse. Eighteen subjects (13.2 per cent) had a lesser degree of posterior systolic motion of the mitral valve leaflets which was suggestive but not diagnostic of prolapse. Minor degrees of posterior systolic mitral valve motion may represent a variant of normal. Caution should be exercised in making the echocardiographic diagnosis of mitral prolapse until this question is settled.

Hypertrophic cardiomyopathy. Evaluation by gated cardiac blood pool scanning.

The gated radionuclide cardiac blood pool scan (GCS) can be used to visualize the entire profile of the interventricular septum and left ventricular contraction. Twenty-two patients with hypertrophic cardiomyopathy, nine with valvular aortic stenosis and six normals, underwent echocardiography and GCS. All patients with hypertrophic cardiomyopathy had asymmetric septal hypertrophy and 14 of 22 had resting systolic anterior motion of the anterior leaflet of the mitral valve on echocardiogram. In eight patients with aortic stenosis with adequate echocardiograms, two had asymmetric septal hypertrophy and none had systolic anterior motion. The GCS demonstrated disproportionate upper septal thickening in 11; septal flattening in 16; cavity obliteration in 17; and a filling defect in the region of the left ventricular outflow tract in 16 of the 22 patients with hypertrophic cardiomyopathy. In the nine patients with valvular aortic stenosis, two demonstrated septal flattening, two cavity obliteration, two an outflow tract defect, and none disproportionate upper septal thickening. Both patients with cavity obliteration demonstrated asymmetric septal hypertrophy on echocardiogram. One normal control patient had septal flattening. Thus the gated cardiac blood pool scan provides an atraumatic technique for the evaluation of patients with hypertrophic cardiomyopathy which complements the echocardiogram.

Correlation of echocardiographic and clinical findings in patients with pericardial effusion.

Clinical data and echocardiographic findings were correlated in 20 patients with pericardial effusion. Moderate to large effusions were associated with increased motion of the entire heart within the pericardial sac. A correlation was found between the estimated volume of fluid and the diastolic excursion and velocity of the right ventricular and left ventricular walls (P less than 0.01). For any given volume of fluid as estimated from the echocardiogram neoplastic effusions resulted in greater increments in wall motion (P less than 0.02). Patterns of "pseudo" mitral valve prolapse occurred and were correlated with the extent and timing of cardiac swinging and heart rate. A diminished E-F slope of the mitral valve echo and notch on the right ventricular epicardial echo during early systole were found in all four patients with pericardial tamponade. These preliminary observations suggest that echocardiographic examination of patients with pericardial effusion may provide clues to the presence or absence of tamponade in addition to providing an estimate of the quantity of fluid in the pericardial sac.