Mechanical adaptation of heart rate change for coronary circulation in patients with and without ventricular hypertrophy.

Yaginuma, Toshio; Noda, Toshitaka; Komatsu, Hiroyuki; Sekiguchi, Hiromichi; Katsuki, Takaaki; Kawada, Yutaka; Watabiki, Toshio; Fujii, Mikihisa; Komaba, Akira; Nishizaki, Takashi; Hosoda, Saichi

doi:10.1253/jcj.53.440

Cited by 2 publications

(1 citation statement)

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“…16,22 These phenomena have been reported by previous investigators and were thought to be caused by an increase in extravascular compression on small coronary vessels during LV systole, as well as different cardiac muscle structures causing increased systolic perivascular resistance. 16,22,23 In evaluating baseline diastolic coronary flow, diastolic coronary flow tended to increase in HCM compared with controls; however, there was no significant difference between the 2 groups in the present study. Several reports have shown that myocardial oxygen consumption and mean coronary flow at rest are significantly higher in patients with HCM than in control subjects, and that the Fig 5.…”

Section: Baseline Coronary Flow In the Lad In Hcm Patientscontrasting

confidence: 66%

Abnormal Coronary Flow Profiles at Rest and During Rapid Atrial Pacing in Patients With Hypertrophic Cardiomyopathy

et al. 1999

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ypertrophic cardiomyopathy (HCM) comprises several different syndromes with varying clinical presentations, natural histories, and pathologic findings. Myocardial ischemia may play a critical role in the symptomatic presentation and the natural history of HCM. [1][2][3] Cannon et al 4 showed that even in the absence of atherosclerotic coronary artery disease, patients with nonobstructive HCM might demonstrate abnormal lactate metabolism during atrial pacing, suggesting that the presence of ischemia is the result of abnormalities of the coronary microcirculation. 5,6 Recent studies have shown that possible mechanisms for this ischemia include intramyocardial small vessel disease, 6-8 septal perforator artery compression, 9 coronary artery spasm, inadequate capillary density in relation to the increased myocardial mass, 10 an increase in systolic perivascular resistance, 11,12 and a limitation to the increase in myocardial blood flow caused by abnormal diastolic relaxation in HCM. 13,14 Furthermore, small vessel coronary artery disease 6-8 with intimal hyperplasia, medial hypertrophy, and impaired coronary flow reserve 9,15,16 may correlate closely with the myocardial ischemia and fibrosis seen in HCM. 15 Cannon et al demonstrated that patients with HCM showed an initial rise in great cardiac vein flow, measured by a thermodilution catheter at an intermediate heart rate of 130 beats/min, but with continued pacing to a heart rate of 150 beats/min, mean coronary flow fell. However, phase analysis of systolic and diastolic coronary flow during tachycardia has not been performed in patients with HCM and the precise mechanism of exercise-induced ischemia remains obscure.The present study was designed to evaluate the mechanisms responsible for myocardial ischemia in patients with nonobstructive HCM by phase analysis of coronary blood flow using a Doppler flow wire at rest and during rapid atrial pacing. Methods Study PatientsWe studied 11 consecutive patients with clinical and echocardiographic evidense of HCM and angiographically normal coronary arteries. The patients underwent transthoracic echocardiographic examinations within 10 days of a diagnostic cardiac catheterization that included coronary arteriography. The patient group included 5 men and 6 women, 24-77 year old (mean, 57±16): 9 patients with asymmetric septal hypertrophy (Maron's classification 17 : type 1, 3 patients; type 2, 4; type 3, 2) with a ventricular septal thickness greater than 15 mm and a ratio of interventricular septum to posterior wall thickness greater than 1.3, and 2 patients with symmetric hypertrophy determined by transthoracic echocardiography. Eight patients presenting with atypical chest pain (5 men and 3 women), 55-67 year old (mean, 63±5) served as control subjects. They did not have significant coronary stenosis or left ventricular hypertrophy, as revealed by selective coronary angiography and echocardiography, respectively. Informed consent was obtained from all patients.Jpn Circ J 1999; 63: 350 -356 (Received October 19, 1998; r...

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