Hemodynamic changes and prognosis in patients with hypertrophic cardiomyopathy and abnormal blood pressure responses during exercise

Abstract

SummaryBackground: An abnormal blood pressure response (BPR) during exercise has been proposed as a risk factor for sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). Some patients with HCM show systolic dysfunction during exercise.Hypothesis: The aim of this study was to clarify the hemodynamic response during exercise and prognosis in patients with HCM and abnormal BPR.Methods: Sixty-five patients with HCM underwent radionuclide monitoring of left ventricular function and measurement of blood pressure during supine ergometer exercise. Thereafter, cardiac events were recorded for an average period of 76 months.Results: Seven of 65 patients had abnormal BPR, while the others had normal BPR. Changes of heart rate and systemic vascular resistance during exercise did not differ between the two groups. Stroke volume did not increase in the abnormal BPR group but did in the normal BPR group. During a mean follow-up period of 76 months, three of the seven patients (43%) with abnormal but only one patient (2%) with normal BPR suffered a malignant arrhythmia.

Exercise-induced systolic dysfunction in patients with non-obstructive hypertrophic cardiomyopathy and mutations in the cardiac troponin genes

“…Moreover, an abnormal blood pressure response is associated with exercise-induced LV systolic dysfunction 13 24. In addition, previous reports have suggested that peak exercise-induced systolic dysfunction in HCM represents a feature of poor prognosis 25.…”

“…Previous studies have suggested that an abnormal blood pressure response during exercise is related to the risk of sudden death and a high prevalence of cardiac events 11 – 13. Moreover, an abnormal blood pressure response is associated with exercise-induced LV systolic dysfunction 13 24.…”

“…Moreover, an abnormal blood pressure response during exercise, which was one of the high risk factors for sudden cardiac death, was associated with exercise-induced LV systolic dysfunction 9 – 13. However, little is known about whether LV functional reserve (response of LV to exercise) before transition to the dilated phase differs among patients with and without disease-causing genes.…”

Relation of Pulse Pressure to Blood Pressure Response to Exercise in Patients With Hypertrophic Cardiomyopathy

“…excessive fall in peripheral/systemic vascular resistance) 19 . It has also been suggested that lower exercise capacity and ABPR in HC may be related to diastolic dysfunction 20 and a blunted augmentation of stroke volume during exercise 21 . Although seemingly paradoxical, these mechanisms may have a single underlying and unifying aetiology related to arterial stiffness.…”

Exercise testing in hypertrophic cardiomyopathy

“…An abnormal blood pressure [8][9][10] and stroke volume [9] response during exercise is a risk factor for sudden cardiac death in HCM patients. Nagata et al [11] reported that abnormal blood pressure response occurred in 11% of their patients with HCM and was associated with a high prevalence of cardiac events. Ha et al [12] reported that augmentation of left ventricular longitudinal function during exercise is blunted in HCM patients, suggesting that longitudinal functional reserve and resting longitudinal function are abnormal in these patients.…”