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Difference in coronary blood flow dynamics between patients with hypertension and those with hypertrophic
Katsushi Misawa1, Yutaka Nitta, Takao Matsubara
1Department of Cardiology, Toyama Red Cross Hospital, Toyama, Japan.
Insights
Coronary blood flow (CBF) dynamics differ between hypertensive left ventricular hypertrophy (LVH) and hypertrophic cardiomyopathy (HCM) patients. The diastolic/systolic velocity ratio distinguishes these conditions, independent of left ventricular mass, impacting coronary circulation.
Area of Science:
- Cardiology
- Physiology
Background:
- Hypertensive left ventricular hypertrophy (LVH) and hypertrophic cardiomyopathy (HCM) are distinct conditions affecting the heart.
- Understanding coronary blood flow (CBF) dynamics is crucial for differentiating these pathologies.
Purpose of the Study:
- To investigate and compare coronary blood flow (CBF) dynamics in patients with hypertensive LVH versus HCM.
- To identify specific CBF parameters that differentiate between hypertensive LVH and HCM.
Main Methods:
- Studied 12 hypertensive LVH patients, 10 HCM patients, and 10 controls with normal coronary arteriograms.
- Measured CBF at rest and after pharmacological vasodilation using Doppler Flo-Wire.
- Analyzed baseline coronary flow reserve, endothelium-dependent vasodilation, and diastolic/systolic velocity ratio.
Main Results:
- Baseline CBF was elevated in both hypertensive LVH and HCM groups compared to controls.
- Coronary flow reserve and endothelium-dependent vasodilation were reduced in both patient groups versus controls, with no inter-group difference.
- The diastolic/systolic velocity ratio at baseline was significantly lower in hypertensive LVH patients than in HCM patients.
Conclusions:
- The diastolic/systolic velocity ratio differs between hypertensive LVH and HCM, irrespective of left ventricular mass.
- Phasic patterns of coronary blood flow (CBF) appear critical in the coronary circulation of patients with hypertensive LVH and HCM.
Abstract:
We studied twelve patients with hypertensive left ventricular hypertrophy (LVH), 10 patients with hypertrophic cardiomyopathy (HCM) and 10 control subjects to examine the differences in coronary blood flow (CBF) dynamics between patients with hypertensive LVH and those with HCM. All subjects had normal coronary arteriograms. Measurements of CBF using Doppler Flo-Wire were performed at rest, and after infusions of acetylcholine and papaverine. The baseline CBF was significantly increased in both hypertensive LVH patients and HCM patients compared to that noted in control subjects (64.1+/-36.9, 80.0+/-38.1, 32.3+/-8.0 ml/min, respectively, p<0.01). Coronary flow reserve and endothelium-dependent vasodilatation were significantly lower in hypertensive LVH patients and HCM patients than in control subjects, but there was no significant difference between the hypertensive LVH and HCM patients themselves. In contrast, the diastolic/systolic velocity ratio at baseline was significantly lower in hypertensive LVH patients than in HCM patients (1.53+/-0.40, 6.31+/-7.50, p<0.05). Although CBF and coronary flow reserve correlated positively and negatively, respectively, with left ventricular mass index (r=0.51, -0.59, respectively), the diastolic/systolic velocity ratio at baseline did not show a significant correlation to left ventricular mass index. In conclusion, the diastolic/systolic velocity ratio differed between hypertensive LVH and HCM patients, independent of left ventricular mass. These results suggest that the difference of phasic pattern of CBF may be essential for coronary circulation in patients with hypertensive LVH and in those with HCM.