Maylene Wong

Abnormal mitral valve coaptation in hypertrophic obstructive cardiomyopathy: proposed role in systolic anterior motion of mitral valve.

Two dimensional echocardiographic evaluation utilizing the apical four chamber and apical long axis views was made in 10 normal subjects and 35 patients with hypertrophic cardiomyopathy, including 16 without and 19 with systolic anterior motion of the mitral valve. Mitral valve leaflets were imaged throughout the cardiac cycle. The normal subjects and the patients with hypertrophic cardiomyopathy without systolic anterior motion demonstrated mitral valve coaptation that seemed to involve the distal tip of the anterior leaflet. In contrast, patients with hypertrophic cardiomyopathy with systolic anterior motion demonstrated abnormal coaptation, so that the posterior leaflet coapted with a mid portion of the anterior leaflet, leaving a distal residual anterior leaflet in the left ventricle during systole. A sharp angulation of this distal leaflet in mid systole toward the interventricular septum is thought to represent systolic anterior motion. It is speculated that abnormal mitral leaflet coaptation in necessary for development of leaflet systolic anterior motion, which is correlated with dynamic left ventricular outflow gradients in hypertrophic obstructive cardiomyopathy.

Doppler evaluation of bioprosthetic and mechanical aortic valves: Data from four models in 107 stable, ambulatory patients

To test the applicability of Doppler ultrasound in the evaluation of prosthetic valve function, 107 patients with normal ejection fractions in whom Starr-Edwards, Björk-Shiley, Carpentier-Edwards, and Hancock models had been implanted in the aortic position were examined. Maximal transvalvular velocity was recorded by non-imaging continuous wave Doppler ultrasound. Means of maximal velocities by model and size ranged from less than 2 to 4 m/sec. The Starr-Edwards valve showed the highest velocities, the Björk-Shiley the lowest, and the bioprosthetic models showed velocities in between. A significant inverse relation between velocity and size, and standard deviations averaging +/- 14% enabled the technique to measure differences between sizes of the same model. Aortic regurgitation was detected in 24% of the patients. This study, conducted in well and stable patients, established values for maximal velocity across normally functioning aortic mechanical and tissue prostheses of different models and sizes. The intersubject variability was relatively small which, together with a previously shown minimal intrasubject variability, was testimony to a methodology that should prove useful in longitudinal postoperative evaluations.

M mode and cross-sectional echocardiographic features of flail posterior mitral leaflets

Seventeen patients with accepted M mode echocardiographic criteria for flail mitral leaflet were studied. M mode echocardiograms revealed characteristic disordered mitral valve motion: (1) 16 (94 percent) had chaotic diastolic mitral motion; (2) 14 (82 percent) had systolic mitral flutter; (3) 14 (82 percent) had systolic left atrial echoes; and (4) 12 (71 percent) had systolic mitral valve prolapse. In 8 patients (47 percent) all four findings were present, with three findings present in 16 (35 percent) and two findings present in 13 (18 percent); none had fewer than two findings. Cross-sectional echocardiographic studies in 10 patients revealed a systolic whipping motion of the posterior mitral leaflet into the left atrium in all, abnormal systolic mitral coaptation in all and an abnormal mass of systolic left atrial echoes in 4. None of the first three M mode criteria were observed in 230 patients with uncomplicated mid systolic click-late systolic murmur syndrome; cross-sectional echocardiography in 30 of 230 patients revealed normal systolic mitral coaptation and no systolic whipping of the tip of the posterior mitral leaflet into the left atrium.

Divergent effects of chronic amiodarone administration on systolic and diastolic function in patients with heart disease.

The purpose of this study was to determine the effects of chronic amiodarone treatment on systolic and diastolic function in patients with cardiac disease undergoing treatment for resistant ventricular arrhythmias. Previous studies have shown that chronic amiodarone treatment either has no effect or increases left ventricular ejection fraction, but the effects on diastolic properties of the ventricle have not been defined. Twelve male patients were given loading doses of amiodarone followed by a maintenance regimen. Serial measurements of heart rate, blood pressure, and indexes of systolic and diastolic function were measured by Doppler echocardiographic techniques at baseline conditions and at 2, 8, and 12 weeks of drug therapy. Changes in altered thyroid state were excluded by serial determinations of thyroid function. Amiodarone increased left ventricular ejection fraction (+16%, p < 0.01 by 8 weeks), decreased presystolic ejection period/left ventricular ejection time (-12%, p < 0.01 by 8 weeks), and increased velocity of circumferential fiber shortening (+22%, p < 0.05 by 8 weeks). Amiodarone decreased mitral inflow velocity peak E/peak A (-7%, p < 0.01 by 12 weeks), and increased deceleration and isovolumic relaxation times incrementally (+36% [p < 0.001] and +23% [p < 0.001], respectively, at 12 weeks). Chronically administered amiodarone can improve systolic function and exert a negative lusitropic action in patients with heart disease.

Reproducibility of stand-alone continuous-wave Doppler recordings of aortic flow velocity across bioprosthetic valves

Continuous-wave Doppler spectra of aortic flow velocity were recorded in duplicate in 20 consecutive patients with aortic porcine valves by 1 technician and 3 occasions: initially and 1 week and 1 month later. The highest maximal aortic velocity recorded from at least 2 transducer locations was taken from 5 consecutive beats that did not vary. The 120 tracings were coded and read by 1 observer. In blinded fashion, 20 records were read twice and 26 were read by 2 interpreters. Variability was calculated from the square root of pooled variances and expressed in meters per second and also related to the mean velocity and expressed as percent coefficient of variation for the following categories: interpretive [intraobserver +/- 0.019 (0.8%), interobserver +/- 0.071 (2.7%)], technical [duplication +/- 0.048 (1.9%)], temporal/biologic [+/- 0.125 (5.0%)]. Doppler measurements of aortic velocity can achieve excellent reproducibility by maintaining constant technique. With a methodologic variability of +/- 2%, the variability associated with the passage of time was significantly different at +/- 5% and was a result of fluctuations in the physiology of a few subjects. Thus, the technique can distinguish small method errors from minor drifts of the biology and, by implication, detect the onset of bioprosthetic degeneration.

Echocardiographic Evaluation of Normal and Prolapsed Tricuspid Valve Leaflets

The tricuspid valve was examined by 2-dimensional (2-D) echocardiography in 14 patients with tricuspid valve prolapse (TVP) and in 16 normal subjects. Individual leaflets were identified anatomically and for frequency of prolapse. Maximal and minimal anular sizes were measured. Multiple tomograms of the tricuspid anulus were recorded at 30 degrees intervals around the tricuspid anulus with the transducer placed at the right ventricular apex. Anuli were reconstructed from the 6 planes and corrected for body surface area. Three leaflets of the tricuspid valve could be anatomically identified in all patients. Prolapse of all 3 leaflets was observed in 6 patients, 2 leaflets in 5 and 1 in 3. Frequency of individual leaflet prolapse was 93% for the septal cusp, 86% for the anterior and 43% for the posterior. Maximal anular circumference and area in TVP were 7.9 +/- 0.6 and 8.9 +/- 1.3 cm2/m2, respectively--significantly larger than values in normal subjects (6.4 +/- 0.5 cm/m2 and 6.1 +/- 0.9 cm2/m2, respectively) (p less than 0.001). Percent reductions in circumference and area in TVP were 14 +/- 3 and 25 +/- 5%, respectively--significantly smaller values than in normal subjects (19 +/- 4 and 33 +/- 4%, respectively). Tricuspid regurgitation (TR) was detected by contrast echocardiography in 7 of 14 patients with TVP. The severity of TR appeared to be minimal in 6 of the 7 patients, and was not associated with an increase in anular size. Thus, TVP is associated with anular dilatation irrespective of associated TR, probably as a primary pathologic characteristic.

Echocardiographic observations of calcium in operatively excised stenotic aortic valves

Qualitative and quantitative 2-dimensional (2-D) echocardiographic methods were developed to define the anatomic and physiologic significance of valvular calcium in aortic stenosis (AS). Qualitative methods assigned etiologic diagnoses by matching patterns of calcium with anatomic criteria. Quantitative techniques measured echodensities from superimposed short-axis views of calcium. Fifty-five pathologic specimens procured from surgery were photographed and radiographed. Etiologic diagnoses were assigned from gross examination and radiodensities were planimetered. Echocardiographic and anatomic diagnoses were compared. Sensitivities for diagnosing the most common etiologies, congenitally bicuspid and degenerative, were 58% and 100% and specificities were 100% and 76%. Calcium tended to be heaviest in congenitally diseased valves and lightest in those with degenerative disease (p less than 0.2) and showed propensity for the right cusp in all etiologies except for those with degenerative disease. Correlation of echodensities to radiodensities was 0.82. The relation of calcific echodensities to orifice area was curvilinear; beyond a level of calcium, further deposits did not reduce the orifice more. A systematic echocardiographic examination of calcium in stenotic aortic valves can give a correct etiologic diagnosis in most patients and identify the severely narrowed orifice.

Diastolic spectrum of left-ventricular hypertrophy : The impact of etiology and coronary artery disease on Doppler transmitral velocity

UNLABELLEDnDiastolic filling of hypertrophied left ventricles has frequently been observed by Doppler methods. We hypothesized that filling characteristics in hypertrophy vary with etiology and concurrent ischemia. For patients with hypertrophy, the left-ventricular ejection fraction was > 0.47 +/- 0.16, end-diastolic pressure was > 15 +/- 2 mm Hg, end-diastolic volume index was < 96 +/- 12 ml/m2 and left-ventricular mass index was 127 +/- 7 g/m2. Peak E (early) and peak A (late) diastolic velocities and E-wave deceleration time, respectively, were as follows (significant unless otherwise indicated): normal subjects (NS), 79 +/- 9 and 82 +/- 19 cm/s, and 151 +/- 7 ms; cardiomyopathic hypertrophy, 63 +/- 16, 83 +/- 15 (NS) and 193 +/- 63, aortic stenosis without coronary disease, 110 +/- 10, 128 +/- 12 and 158 +/- 22 (NS); aortic stenosis with coronary disease, 57 +/- 12, 86 +/- 26 (NS) and 187 +/- 39; hypertension without coronary disease, 107 +/- 9, 128 +/- 9 and 143 +/- 22 (NS); hypertension with coronary disease, 58 +/- 12, 84 +/- 26 (NS) and 189 +/- 29.nnnCONCLUSIONSnHypertrophied left ventricles filled with two diastolic Doppler patterns: a relaxation abnormality with low peak E and delayed deceleration in hypertrophic cardiomyopathy, and a compliance abnormality with tall peak E and normal deceleration in pressure overload hypertrophy. When coronary artery disease occurred with pressure overload hypertrophy, impaired relaxation was the dominant pattern. Therefore, in addition to the known physiologic influences on diastolic filling, the etiology and presence of coronary artery disease modulate the configuration of transmitral velocities into hypertrophied ventricles.