Transesophageal echocardiographic evaluation of mitral regurgitation in hypertrophic cardiomyopathy: contributions of eccentric left ventricular hypertrophy and related abnormalities of the mitral complex

Impact of gender on the left ventricular cavity size and contractility in patients with hypertrophic cardiomyopathy

BACKGROUND

The aim of the study was to assess gender-specific differences in left ventricular cavity size, contractility and left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy.

METHODS

We studied retrospectively 129 referred patients with hypertrophic cardiomyopathy (77 males and 52 females). The echocardiographically measured left ventricular end-systolic, end-diastolic dimensions, fractional shortening and occurrence of left ventricular outflow tract gradient > or =30 mmHg were compared between sexes. Logistic regression analysis was used to calculate the predictive values of left ventricular dimensions and contractility for left ventricular outflow tract obstruction for each gender separately.

RESULTS

Left ventricular end-diastolic and end-systolic dimensions were significantly smaller in females than males (41.7+/-5.3 vs. 45.1+/-4.9 mm, P=0.0003; 23.1+/-44 vs. 25.6+/-5.3 mm, P=0.007 respectively). On the contrary, the value of fractional shortening was comparable in both sexes (44.7+/-7.3 vs. 43.6+/-7.9%, P>0.05). The left ventricular outflow tract gradient occurred in females as frequently as in males (28.8 vs. 33.8%, P>0.05). By logistic regression analysis the predictors of left ventricular outflow tract gradient in females were left ventricular end-systolic diameter (relative risk=0.74; confidence interval (CI) 0.61 to 0.91; P=0.0038), left ventricular end-diastolic diameter (relative risk=0.82; CI 0.72 to 0.96; P=0.0061) and fractional shortening (relative risk=1.11; CI 1.01 to 1.22; P=0.036). The most potent predictor appeared to be left ventricular end-systolic dimension. In males none of these parameters identified patients with left ventricular outflow tract obstruction.

CONCLUSIONS

Females with hypertrophic cardiomyopathy featured smaller left ventricular cavity size, which predisposed to left ventricular outflow tract obstruction (the most potent predictor of left ventricular outflow tract obstruction was left ventricular end-systolic dimension). Higher left ventricular contractility also determined left ventricular outflow tract gradient occurrence in females with hypertrophic cardiomyopathy. In males despite a larger left ventricular cavity size the left ventricular outflow tract obstruction occurred with a similar frequency as in females. Left ventricular outflow tract obstruction was not predicted by left ventricular cavity size or contractility in males.

Mitral regurgitation in hypertrophic obstructive cardiomyopathy: relationship to obstruction and relief with myectomy

OBJECTIVES

This study examined: 1) the impact of myectomy on postoperative mitral regurgitation (MR) and 2) the association between the severity of MR and the left ventricular outflow tract (LVOT) gradient.

BACKGROUND

For patients with hypertrophic obstructive cardiomyopathy (HOCM) and MR, controversy exists as to whether myectomy alone is sufficient in eliminating MR. Furthermore, the relationship between the degree of MR and the LVOT peak gradient has not been well defined.

METHODS

We performed pre- and postoperative transthoracic as well as intraoperative transesophageal studies in 104 consecutive patients with HOCM undergoing septal myectomy. Left ventricular outflow tract gradient and the nature of MR were assessed.

RESULTS

In the 93 patients without independent mitral valve disease, a relationship was observed between MR severity and the LVOT gradient. Left ventricular outflow tract gradient (mean +/- standard deviation) for trivial, mild, moderate and severe MR were: 23.2+/-19.1, 43.8+/-25.4, 70.1+/-21.0 and 104+/-21.0 mm Hg (p < 0.001). Early postoperative, MR was absent or trivial in 80%, mild in 19% and moderate in 1%. None of these patients required additional mitral valve surgery. For patients with independent mitral valve disease (n = 11), five required mitral valve surgery as well as myectomy. The remainder had significant reductions in the degree of MR with myectomy alone.

CONCLUSIONS

For patients with HOCM and MR not due to independent mitral valve disease, myectomy significantly reduced the degree of MR, without requirement for additional mitral valve surgery. In these patients the severity of MR was directly related to the magnitude of the LVOT gradient.

Hypertrophic cardiomyopathy with obstruction: important diagnostic clue provided by the direction of the mitral regurgitation jet

We present an unusual case of hypertrophic cardiomyopathy complicated by mitral regurgitation resulting from chordal rupture with flail posterior mitral leaflet. The diagnosis was suggested by the presence of an anteriorly directed mitral regurgitation jet on transthoracic color flow imaging, in addition to the typical posterolateral-lateral jet caused by systolic anterior mitral motion. The flail posterior leaflet was confirmed by transesophageal echocardiography, and the patient underwent mitral valve repair in addition to myectomy. This combination of hypertrophic cardiomyopathy and flail mitral leaflet usually requires surgical intervention, and prompt diagnosis is important. The presence of an anteriorly directed mitral regurgitant jet should always raise suspicion of posterior mitral leaflet abnormality.