Toshiji Iwasaka

Effect of exercise on ventricular diastolic time in coronary artery disease.

To evaluate diastolic time during uninterrupted upright exercise, 28 normal volunteers (group 1) and 12 men with coronary artery disease (group 2) were studied by ear densitography. Electromechanical systole-heart rate and diastolic time-heart rate regression equations during upright exercise were obtained from group 1. Electromechanical systole-heart rate had an inverse linear relation (electromechanical systole = 480 - 1.4 heart rate) and diastolic time-heart rate had an inverse nonlinear relation (diastolic time = 1206e-0.02 heart rate). Although there were no significant differences in electromechanical systole and diastolic time at 1 minute of exercise between patients with and without CAD, at peak exercise prolongation of electromechanical systole and consequent shortening of diastolic time in patients with CAD were observed. This disproportionate shortening of diastole with lengthening of systole at peak exercise tends to decrease myocardial perfusion and, hence, oxygen supply, while increasing myocardial oxygen demand, contributing to aggravation of ischemia in patients with CAD.

Diastolic time during recovery from upright exercise in persons without heart disease

To assess the relation between heart rate and diastolic time (cardiac cycle minus electromechanical systole) during the recovery period from upright exercise, 12 normal volunteers were studied immediately after and 2 and 5 minutes after exercise in the upright position. Although heart rate was significantly lower at 5 minutes compared with 2 minutes after exercise (106 vs 116 beats/min), there was significant shortening of diastolic time (from 251 to 230 ms) and total diastole per minute (from 28,634 to 24,220 ms/min). The explanation of this phenomenon appears to be disproportionate lengthening of diastolic time at 2 minutes after exercise, which must represent physiologic response due to increased left ventricular filling as well as continuing adrenergic effects, which would be diminished at 5 minutes. This lengthening of diastolic time also would maintain decreased subendocardial blood flow caused by increased end-diastolic volume.

Critical appraisal and pooled analysis of telmisartan alone or in combination with hydrochlorothiazide for achieving blood pressure goals

Rigid control of blood pressure (BP) is essential to prevent cardiovascular disease. However, only about 40% of hypertensive patients undergoing pharmacological intervention with a single agent achieve their BP goals in contemporary clinical practice. Combined therapy using currently available agents is effective in maximizing treatment outcome, although it raises medical costs and decreases the drug compliance rate. To overcome such negative consequences, a combination tablet containing an angiotensin II receptor blocker (ARB) with a small dose of hydrochlorothiazide (HCTZ) is now available on the international market, including Japan. This article briefly describes the unique properties of telmisartan, a highly selective ARB for the angiotensin II type 1 receptor, including its long-acting characteristics and recent prospective multicenter randomized clinical trials, followed by a description of a newly-introduced combination tablet in Japan, which contains telmisartan and HCTZ. This article also reviews its safety and efficacy based on currently available evidence. Finally, evidence comparing telmisartan/HCTZ with other combination therapies is presented.