Hemodynamic basis of mitral E transmission in the left ventricular cavity and its relation to the left ventricular relaxation process

Mitral E-wave transit time to the left ventricular outflow tract was measured as an E-Er interval in 30 subjects undergoing cardiac catheterization. The E-Er interval (range 30 to 190 ms) correlated with left ventricular peak negative dP/dt (r = -0.62, p = 0.0003) and tau (r = 0.74, p <0.0001) but not with left ventricular minimum, pre-A-wave, or end-diastolic pressures. We conclude that the E-Er interval is an easily obtainable Doppler measurement that reflects the left ventricular relaxation process.

A rare case of inferior venacaval type of atrial septal defect in an adult: echocardiographic features

We report a rare type of atrial septal defect with communication between the left atrium and the inferior vena cava. This type of defect has been referred to as a low sinus venous type of atrial septal defect because of its developmental origin, and possibly is caused by defective absorption of the left venous valve of the sinus venosus into the septum secundum. Detailed echocardiographic features are discussed.

Effect of atrial fibrillation on the dynamics of mitral annular area

BACKGROUND AND AIMS OF THE STUDY

The mitral annulus shows dynamic changes in shape and size during the cardiac cycle. A smaller size in end-diastole is attributed to the sphincteric action of atrial systole, and this may be important for functional integrity of the mitral valve. However, the effect of atrial fibrillation (AF) on dynamic changes in mitral annular size in humans is not known.

METHODS

Mitral annular diameters in apical four- and two-chamber views were measured using echocardiography in 25 patients in atrial fibrillation, and in 37 subjects in normal sinus rhythm at mid-diastole, end-diastole and end-systole. Mitral annular area was computed assuming elliptical geometry.

RESULTS

Patients in sinus rhythm showed a significant increase in mitral annular area of 25.9 +/- 12.8% with ventricular systole compared to its area in end-diastole (p < 0.0001), and a 10.5 +/- 8.4% reduction with atrial systole compared to mid-diastole (p < 0.001). Patients in AF had larger mitral annuli which showed non-significant changes in size between these three phases of the cardiac cycle. Percent reduction in mitral annular area in the latter half of diastole correlated significantly with left atrial (LA) diameter (r = -0.54, p < 0.0001), LA volume (r = -0.50, p < 0.0001), left ventricular (LV) fractional shortening (r = 0.37, p = 0.0036), mitral annular area in mid-diastole (r = -0.41, p = 0.0011) and mitral annular area in end-diastole (r = -0.64, p < 0.0001). That is, atrial sphincteric action on the mitral annulus was less in the presence of larger left atrium or the mitral annulus. Stepwise multiple regression analysis showed rhythm and mitral annular size to be independent predictors of dynamic changes in mitral annular area.

CONCLUSION

It is concluded that AF blunts or eliminates the phasic changes in mitral annular size during the cardiac cycle with loss of its presystolic sphincteric action; this may have implications in the genesis and surgical correction of mitral regurgitation.

Diastolic Heart Failure Mechanisms and Assessment Revisited

The syndrome of heart failure (HF) with preserved ejection fraction (HFpEF) makes up about half of the HF population. The HF mechanisms in these patients are varied and not fully understood. In addition, the term "diastolic HF" was switched to HFpEF because of difficulties in measuring the left ventricular (LV) diastolic performance. In the late stages, HFpEF carries a prognosis that is as bad as or worse than that of HFrEF. Hence, it is important to recognize LV diastolic impairment at an earlier stage so that the causal mechanisms, if any, can be treated to retard its progression. Despite the availability of numerous disease-modifying agents for HFrEF, there are hardly any available treatments for HFpEF. With our aging population, there will be an epidemic of HFpEF and hence this entity needs attention and respect. In this paper, we review the fundamental mechanisms of HFpEF, the physiology of LV filling and how LV diastolic function can be comprehensively measured. We also speculate how this may help with the early recognition of diastolic HF and its treatment.

Importance of concomitant functional mitral regurgitation on survival in severe aortic stenosis patients undergoing aortic valve replacement

BACKGROUND

Mitral regurgitation (MR) is commonly seen in patients with severe aortic stenosis (AS) undergoing aortic valve replacement (AVR). But the long-term implications of MR in AS are unknown.

AIM

To investigate MR's impact on survival of patients undergoing surgical AVR for severe AS.

METHODS

Of the 740 consecutive patients with severe AS evaluated between 1993 and 2003, 287 underwent AVR forming the study cohort. They were followed up to death or till the end of 2019. Chart reviews were performed for clinical, echocardiographic, and therapeutic data. MR was graded on a 1-4 scale. Mortality data was obtained from chart review and the Social Security Death Index. Survival was analyzed as a function of degree of MR.

RESULTS

The mean age of the severe AS patients who had AVR (n = 287) was 72 ± 13 years, 46% women. Over up to 26 years of follow up, there were 201 (70%) deaths, giving deep insights into the determinants of survival of severe AS who had AVR. The 5, 10 and 20 years survival rates were 75%, 45% and 25% respectively. Presence of MR was associated with higher mortality in a graded fashion (P = 0.0003). MR was significantly associated with lower left ventricular (LV) ejection fraction and larger LV size. Impact of MR on mortality was partially mediated through lower LV ejection fraction and larger LV size. By Cox regression, MR, lower ejection fraction (EF) and larger LV end-systolic dimension were independent predictors of higher mortality (χ2 = 33.2).

CONCLUSION

Presence of greater than 2+ MR in patients with severe AS is independently associated with reduced survival in surgically managed patients, an effect incremental to reduced EF and larger LV size. We suggest that aortic valve intervention should be considered in severe AS patients when > 2+ MR occurs irrespective of EF or symptoms.