Masahide Matsutani

Effect of Cilostazol in preventing restenosis after percutaneous transluminal coronary angioplasty

This study sought to evaluate the effect of cilostazol in preventing restenosis after successful percutaneous transluminal coronary angioplasty (PTCA) in 68 patients: 35 patients received cilostazol immediately after PTCA and 33 patients received aspirin or ticlopidine. Repeat coronary angiography was performed 4 to 6 months after PTCA and the incidence of restenosis was significantly lower (17%) in the cilostazol group than in the non-cilostazol group (40%) (p < 0.05), which indicates that cilostazol has the potential to prevent restenosis after PTCA.

Atrial fibrillation in inferior wall Q-wave acute myocardial infarction.

Abstract Although atrial fibrillation (AF) is a relatively common arrhythmia occurring during the course of acute myocardial infarction (AMI), the mechanisms involved in its genesis remain controversial and are mostly focused on the left ventricle and atrium: left ventricular failure, pericarditis and left atrial ischemia.1–4 In contrast, the role of hemodynamic change imposed on the right ventricle and right atrium related to the onset of AF after AMI is poorly understood. Because hemodynamic change of the right ventricle is often observed in inferior AMI, we hypothesized that hemodynamic impairment, audible pericardial friction rub, electrocardiographic evidence of right ventricular AMI and age may be important clinical factors associated with the occurrence of AF. In this study, multivariate analysis was used to assess the clinical settings associated with the occurrence of AF in patients with their first Q-wave inferior AMI.

Factors associated with atrial fibrillation in Q wave anterior myocardial infarction

To elucidate the role of inflammatory and hemodynamic factors in the genesis of atrial fibrillation in acute myocardial infarction, 228 patients with a first Q wave anterior myocardial infarction were studied. Forty-nine patients had pericarditis (detection of pericardial rub by careful auscultation), and 36 patients had echocardiographically demonstrated hydropericardium (presence of pericardial effusion without pericardial rub). During the first 3 days after admission, transient episodes of atrial fibrillation were observed in 10 patients (20%) with pericarditis (group 1), 15 patients (42%) with hydropericardium (group 2), and 20 patients (14%) without pericarditis and hydropericardium (group 3). Although there was no significant difference in the incidence of atrial fibrillation between groups 1 and 3, patients in group 2 had a significantly higher incidence of atrial fibrillation than those in groups 1 and 3. Pulmonary capillary wedge pressure and the number of advanced asynergic segments were found to be the important factors discriminating the three groups by multivariate analysis. Therefore atrial fibrillation after acute Q wave anterior infarction was not related to the inflammatory infiltration involving the atria but to the increase in atrial pressure resulting from hemodynamic change caused by more extensive myocardial damage.

Factors associated with pericardial effusion in acute Q wave myocardial infarction.

To elucidate the clinical characteristics associated with pericardial effusion in the early phase of myocardial infarction, 330 patients with acute Q wave infarction were studied. According to echocardiography, 83 patients had pericardial effusion on the third day of hospitalization, and careful auscultation revealed that a pericardial rub was absent in 45 patients and was present in 38 patients. Based on seven clinical variables, multivariate analysis was performed to determine the important variables related to the occurrence of pericardial effusion with and without pericardial rub. Pulmonary capillary wedge pressure and left ventricular segments with advanced asynergy were the significant factors related to the occurrence of pericardial effusion without a pericardial rub. The presence of ventricular aneurysmal motion, left ventricular segments with advanced asynergy, and alveolar arterial oxygen difference were related to pericardial effusion with a pericardial rub. Therefore, a hemodynamic factor was the major mechanism associated with the increase in extravascular myocardial fluid and the consequent occurrence of hydropericardia in the absence of a pericardial rub, whereas an increase in the microvascular permeability in the myocardium with excessive fluid exudating through the irritated epicardial surface was the mechanism related to pericardial effusion with a pericardial rub in the early phase of acute myocardial infarction.

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.

Factors associated with persistent and transient fascicular blocks in anterior wall acute myocardial infarction

To determine the factors associated with persistent and transient fascicular blocks, 144 patients with Q-wave anterior wall acute myocardial infarction (AMI) were studied. Thirty-three patients had new onset of fascicular block considered to be a consequence of AMI. Multivariate analysis using 16 clinical variables revealed that the number of asynergic segments, serum potassium level and pericardial rub were significant factors related to the occurrence of fascicular block. Among the 33 patients with fascicular block, 18 had persistent (group 1) and 15 had transient (group 2) fascicular blocks. When the 2 groups with fascicular block were compared, group 1 had significantly more asynergic segments than group 2 (4.7 +/- 1.2 vs 3.7 +/- 1.6, respectively), whereas pericardial rubs were observed significantly more in group 2 (67%) than in group 1 (28%). Therefore, the inflammatory process of AMI was 1 of the mechanisms related to the occurrence of a transient fascicular block and a more extensive myocardial necrosis was associated with a persistent fascicular block.

Factors associated with late onset of advanced atrioventricular block in acute Q wave inferior infarction

To elucidate the clinical characteristics associated with advanced atrioventricular (AV) block that appears relatively late (more than 24 hours) after the onset of myocardial infarction (MI), 101 patients with acute Q wave inferior MI were studied. Fourteen patients had late-onset advanced AV block, and 87 patients were free of AV block. The hospital mortality rate was 11%. Multivariate analysis was performed to determine the important variables associated with the occurrence of late advanced AV block and hospital mortality rates based on 12 clinical variables. Colloid osmotic pressure, right atrial pressure, serum potassium level, and number of segments with advanced asynergy were the significant factors associated with the occurrence of late advanced AV block, whereas advanced asynergic segments and alveolar arterial oxygen difference were important in the consideration of hospital mortality rates. Therefore not only the extent of myocardial ischemia but also the increases in the extracellular potassium level and interstitial fluid are some of the factors that are associated with the occurrence of late advanced AV block in acute inferior MI. Late advanced AV block, in itself, has no significant influence on hospital mortality rates.

Left Ventricular Dysfunction during Dynamic Exercise in Noninsulin-Dependent Diabetic Patients with Retinopathy

Systolic time intervals were obtained from 19 middle-aged noninsulin-dependent diabetic patients without clinically evident cardiovascular disease (8 patients had and 11 did not have retinopathy) and 14 normal subjects using ear densitography. All subjects had neither ischemic electrocardiographic response nor chest pain during maximal treadmill exercise. Although left ventricular ejection time (LVET) and preejection period (PEP) did not differ significantly at rest between the three groups, a prolongation of LVET with a nearly identical PEP response was observed during exercise in diabetic patients with retinopathy. These data indicate that the diabetic patients with retinopathy relied on the enhanced ventricular filling in maintaining stroke volume during exercise. Thus, retinopathy is associated with impaired left ventricular systolic function in noninsulin-dependent diabetic patients.

Effect of propranolol on diastolic time during exercise

To evaluate the effect of propranolol on diastolic time (DT) during uninterrupted upright exercise, 11 men with normal coronary arteries receiving oral propranolol and 1.0 men with coronary artery disease (CAD) were studied by ear densitography. The DT-heart rate (HR) regression equation during exercise obtained from persons without CAD receiving propranolol was DT = β, which was not statistically different compared to that of normal volunteers with no medication. All 10 men with CAD had ischemic electrocardip-graphic responses at peak exercise with no medication but had no signs of ischemia during exercise after receiving oral propranolol therapy. Although propranolol caused no significant difference in the DT-HR relation in patients with CAD at 1-min exercise, a significant difference in the DT-HR relation was observed after propranolol therapy at peak exercise. In addition to negative chronotropic action (leftward shift along the DT-HR curve), prevention of disproportionate DT shortening at peak exercise (upward shift of the DT-HR curve) with propranolol through its beneficial action on myocardial ischemia tends to increase myocardial perfusion in patients who, when off propranolol, had ischemic response to exercise.

Diastolic time and systolic time intervals during static exercise in the late hospital phase of acute myocardial infarction

To evaluate diastolic time (DT) during static exercise, the DT-heart rate relation was studied by ear densitography in the late hospital phase of acute myocardial infarction. None of the patient had an ischemic electrocardiographic response