Diastolic coronary vasodilator reserve was decreased in the hypertrophied HCM-LAD region (46% of control) but not in the HCM-LCx region (86% of control), detecting microcirculatory changes.
Observational (n=20)
Does diastolic coronary vasodilator reserve (DCVR) detect regional microcirculatory changes in patients with hypertrophic cardiomyopathy?
Diastolic coronary vasodilator reserve (DCVR) is a novel physiological index that can specifically detect regional microcirculatory disturbances in hypertrophied myocardium, offering advantages over standard coronary flow reserve.
OBJECTIVES: The present study introduces a modification of the diastolic coronary conductance concept that maintains its sensitive properties to detect changes in the coronary microcirculation in human hypertrophy. BACKGROUND: Decrements of coronary flow in hypertrophy have been explained by changes in the coronary microcirculation. No measure is available to detect these changes. METHODS: Doppler velocity catheters were introduced into the left anterior descending artery (LAD) and left circumflex coronary artery (LCx) of patients with obstructive hypertrophic cardiomyopathy (HCM) (n = 11) and into the LAD of cardiac transplant recipients (n = 9). The diastolic coronary conductance was measured at rest and after maximal hyperemia induced by a bolus injection of adenosine. Diastolic coronary vasodilator reserve (DCVR) was calculated as the hyperemic diastolic coronary conductance, divided by the coronary conductance during resting conditions. RESULTS: Left ventricular outflow tract gradient in the HCM group (83 +/- 31 mm Hg) was significantly higher (p 0.05). Esmolol did affect the pressure gradient and systolic shortening, but did not affect the maximal diastolic conductance. CONCLUSIONS: The DCVR, in contrast with the coronary flow reserve, is decreased in those regions that display a disturbance in the microcirculation and may, therefore, offer a new way to study coronary adaptations in patients with hypertrophy.
Krams et al. (Sun,) conducted a observational in Hypertrophic cardiomyopathy (n=20). Diastolic coronary vasodilator reserve (DCVR) measurement vs. Cardiac transplant recipients (control) was evaluated on Diastolic coronary vasodilator reserve (DCVR). Diastolic coronary vasodilator reserve was decreased in the hypertrophied HCM-LAD region (46% of control) but not in the HCM-LCx region (86% of control), detecting microcirculatory changes.