Dynamic Intracavity Gradients: A ‘New’ Hemodynamic Abnormality in the Spectrum of Secondary Left Ventricular Hypertrophy

Abstract

The effect of provocation on left ventricular (LV) outflow was studied by continuous-wave Doppler echocardiography in 93 patients with LV hypertrophy (LVH), either due to pressure overload or hypertrophic cardiomyopathy (HCM), and in 39 healthy volunteers. In 50 patients with LVH, outflow acceleration (gradients ranging from 19 to 130 mm Hg) was induced or accentuated by at least one provocative situation independently of LVH aetiology. In normal persons LV outflow remained unchanged. Calcium antagonist treatment reduced outflow acceleration. It is concluded that dynamic LV gradients are a non-specific flow abnormality in the spectrum of LVH that merits consideration.

Outflow Acceleration Assessed by Continuous-Wave Doppler Echocardiography in Left Ventricular Hypertrophy: An Analysis of 103 Consecutive Cases

“…As far as the determinants for LV outflow acceleration in secondary LVH are concerned, previous research has shown that relative LV wall thickness, SAM, and resting LVOT flow characteristics were associated with this hemodynamic abnormality [21, 28]. In this larger and nonselected patient group, female sex, a small body surface area and LV cavity size, mitral anulus calcifications and a high contractility have additionally been identified as risk factors for overt or provocable outflow acceleration.…”

“…There seem to be different mechanisms and sites of gradient formation in the various types of LVH [21, 22]. In patients with aortic valve disease [23, 24], after reconstruction or replacement of the mitral valve [25], in patients with cardiac amyloidosis [26]or pericardial tamponade [27], intracavity pressure differences have been documented by invasive or Doppler methods.…”

“…Patients displaying systolic and diastolic flow abnormalities reminiscent of obstructive HCM and associated with LVH due to long-standing arterial hypertension have been labeled as suffering from hypertensive HCM, a term discussed controversially by several investigators [1, 2, 21, 28, 29, 30, 31, 32]. Provocation by preload reduction, as compared to physical strain, has resulted in similar outflow acceleration in patients with secondary LVH [21], thus indicating that these outflow gradients may also be present under physiologic conditions.…”

“…Provocation by preload reduction, as compared to physical strain, has resulted in similar outflow acceleration in patients with secondary LVH [21], thus indicating that these outflow gradients may also be present under physiologic conditions.…”

“…Previous studies on this subject, however, have included highly selected patient groups [21, 22, 28]; consequently, a clear statement on the quantitative dimension of the problem was not possible. Our findings may fill the gap concerning the frequency of overt or latent LVOT gradients in nonselected patients with LVH.…”