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[Coronary flow characteristics in hypertrophic cardiomyopathy--a study with Doppler catheter]
K Negishi1, S Handa, Y Asakura
1Department of Internal Medicine, School of Medicine, Keio University.
Insights
Hypertrophic cardiomyopathy (H) shows altered coronary flow patterns with reduced coronary flow reserve compared to non-cardiac chest pain (N). Specifically, H exhibits systolic backward flow and lower peak to resting velocity ratios (PRVR) in the LAD artery.
Area of Science:
- Cardiology
- Hemodynamics
- Cardiovascular Physiology
Context:
- Hypertrophic cardiomyopathy (H) is a complex condition affecting heart muscle structure and function.
- Assessing coronary blood flow is crucial for understanding cardiac health and diagnosing various conditions.
- Non-obstructive coronary artery disease can present with symptoms similar to other cardiac pathologies.
Purpose:
- To compare the coronary flow patterns and coronary flow reserve between patients with hypertrophic non-obstructive cardiomyopathy (H) and those with non-cardiac chest pain (N).
- To investigate the hemodynamic differences in coronary arteries using Doppler velocimetry.
Summary:
- Coronary flow patterns were analyzed in the left anterior descending (LAD), circumflex (LCX), and right coronary arteries (RCA) using a catheter-tip Doppler velocimeter.
- Patients with H demonstrated a more prominent diastolic coronary flow pattern with systolic backward flow in the LAD, leading to a significantly decreased systolic to diastolic area ratio (*s/*d) compared to N.
- In H, diastolic peak velocity (Vd) and mean velocity (Vm) in the LAD were higher, but the peak to resting velocity ratio (PRVR), an index of coronary flow reserve, was significantly lower than in N.
Impact:
- This study highlights distinct coronary hemodynamic alterations in hypertrophic cardiomyopathy, differentiating it from non-cardiac chest pain.
- Findings suggest impaired coronary flow reserve in H, potentially contributing to myocardial ischemia.
- The results provide valuable insights for the diagnosis and management of patients with hypertrophic cardiomyopathy and chest pain.
Unlabelled:
We compared the pattern and reserve of coronary flow in 8 cases of hypertrophic non-obstructive cardiomyopathy (H) with those in 20 cases of chest pain not accompanied by organic heart disease (N). A catheter-tip Doppler velocimeter was positioned in the proximal portion of the left anterior descending (LAD), circumflex (LCX) and right coronary (RCA) arteries. Coronary flow velocity (Vs: systolic peak, Vd: diastolic peak, Vm: mean) was recorded and the area under the velocity curve was divided into systole (* s) and diastole (* d). The time interval between the dicrotic notch in aortic pressure and the peak of diastolic flow velocity was measured (Tpv). Vm was measured before and after intracoronary injection of 6 ml of contrast media, and peak to resting velocity ratio (PRVR) was calculated as an index of coronary flow reserve.
Result:
In LAD, N showed diastolic predominant coronary flow pattern without backward flow. In H, diastolic predominance was more prominent with systolic backward flow, resulting in decrease in * s/* d(H: 0.07 +/- 0.04, N: 0.25 +/- 0.02, p less than 0.01). In H, Vd (H: 20.1 +/- 2.8, N: 9.2 +/- 1.4 cm/sec, p less than 0.05) and Vm(H: 9.5 +/- 1.3, N: 4.9 +/- 0.7 cm/sec, p less than 0.05) were higher, while PRVR was lower (H: 1.7 +/- 0.1, N: 2.6 +/- 0.1, p less than 0.05). In both N and H, the flow pattern of LCX was diastolic predominant with two peaks (one in systole and the other in diastole).(ABSTRACT TRUNCATED AT 250 WORDS)