Effect of nicorandil on left ventricular end-diastolic pressure during exercise in patients with hypertrophic...

Area of Science:

• Cardiology
• Pharmacology
• Exercise Physiology

Background:

• Impaired coronary microcirculation contributes to myocardial ischemia in hypertrophic cardiomyopathy (HCM).
• Abnormal increases in left ventricular end-diastolic pressure (LVEDP) during exercise are characteristic of HCM.
• Understanding treatments that improve exercise hemodynamics in HCM is crucial.

Purpose of the Study:

• To evaluate the effects of nicorandil on LVEDP during exercise in patients with nonobstructive HCM.
• To assess nicorandil's impact on exercise-induced ischemia and coronary microcirculation in HCM.

Main Methods:

• 23 patients with nonobstructive HCM underwent supine bicycle exercise with simultaneous hemodynamic measurements.
• Intravenous nicorandil or propranolol was administered, and measurements were repeated.
• Exercise thallium-201 scintigraphy assessed ischemic burden; patients were grouped by LVEDP response.

Main Results:

• Group I (n=13) showed progressive LVEDP increase during exercise, while Group II (n=10) had biphasic changes.
• Group I had greater left ventricular hypertrophy and ischemic burden than Group II.
• Nicorandil administration resulted in biphasic LVEDP changes in 4/8 Group I patients, unlike propranolol in Group II patients.

Conclusions:

• Nicorandil demonstrates a beneficial effect on exercise-induced LVEDP alterations in HCM patients.
• These findings suggest nicorandil may improve diastolic function and reduce ischemia during exercise in HCM.