Dynamic changes in left ventricular outflow tract flow velocities after amyl nitrite inhalation in hypertrophic cardiomyopathy
| Autor: | Stavros Hadjimiltiades, Michael McAllister, John Ross, Ioannis P. Panidis, Gary S. Mintz |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Adult
Male medicine.medical_specialty Adrenergic beta-Antagonists Hemodynamics Doppler echocardiography Ventricular Function Left Pentanols Internal medicine Administration Inhalation medicine Ventricular outflow tract Humans Systole Aged Nitrates medicine.diagnostic_test business.industry Hypertrophic cardiomyopathy Blood flow Cardiomyopathy Hypertrophic Middle Aged medicine.disease Echocardiography Doppler Blood pressure Echocardiography Cardiology Cardiology and Cardiovascular Medicine business Amyl nitrite Blood Flow Velocity medicine.drug |
| Zdroj: | American heart journal. 121(4 Pt 1) |
| ISSN: | 0002-8703 |
| Popis: | Doppler echocardiography was performed in 21 patients with hypertrophic cardiomyopathy (HC), in nine patients with no evidence of left ventricular (LV) hypertrophy by two-dimensional echocardiography, and in five patients with systemic hypertension and concentric LV hypertrophy. The LV outflow tract (LVOT) peak velocity was recorded by continuous wave Doppler technique at rest and after amyl nitrite inhalation. The LVOT pressure gradient was calculated by the modified Bernoulli equation. A significant increase in heart rate and a drop in systolic blood pressure were observed in all patients after amyl nitrite inhalation; no adverse effects were encountered. The peak LVOT velocity and pressure gradient increased significantly after provocation in all patients, but the increase was much more pronounced in patients with HC (peak LVOT velocity increased from 2.2 +/- 0.8 to 4.3 +/- 1.0 m/sec and peak gradient increased from 22 +/- 17 to 78 +/- 36 mm Hg). The Doppler spectral signal in patients with HC demonstrated a characteristic contour, with peak velocity occurring in late systole. However, the observed increase in LVOT peak velocity was not statistically different between treated (with beta-blockers and calcium blockers) and untreated patients with HC. We conclude that LVOT peak velocity and pressure gradients in patients with HC can be readily assessed by Doppler echocardiography both at rest and after amyl nitrite inhalation. The dynamic changes in LVOT velocity induced by this provocation have certain characteristic features in obstructive HC but appear to be independent of the medical regimen used, at least in the dosages tested in our study. |
| Databáze: | OpenAIRE |
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