Makoto Akaishi

C-Reactive Protein as a Predictor of Infarct Expansion and Cardiac Rupture After a First Q-Wave Acute Myocardial Infarction

BACKGROUND Pump failure after acute myocardial infarction (AMI) can be predicted by several indices that estimate infarct size. However, there are few indices that predict infarct expansion and cardiac rupture. We focused on the prognostic significance of serum C-reactive protein (CRP) after AMI. METHODS AND RESULTS Serum CRP levels were measured every 24 hours in 220 patients with a first Q-wave AMI. In-hospital complications, predischarge left ventriculographic findings, and long-term prognosis were assessed in relation to peak CRP levels. Peak levels of both CRP and creatine kinase (CK) were higher in patients with pump failure than in those without pump failure. In patients with cardiac rupture, peak CRP levels were higher than in those without rupture (P=.001); peak CK levels were not predictive. Higher CRP levels were found in patients with left ventricular aneurysm (P=.001 versus those without), aggravated heart failure (P=.03 versus those without), and cardiac death (P<.0001 versus survivors) during the first year after AMI. Multivariate analysis confirmed that an elevation of the peak CRP level > or = 20 mg/dL was an independent predictor of cardiac rupture (relative risk, 4.72; P=.004), left ventricular aneurysmal formation (relative risk, 2.11; P=.03), and 1-year cardiac death (relative risk, 3.44; P<.0001). CONCLUSIONS Cardiac rupture, left ventricular aneurysmal formation, and 1-year cardiac death were associated with an elevation of serum CRP early after AMI, suggesting that elevation of CRP levels after AMI may predict infarct expansion.

Preinfarction angina as a major predictor of left ventricular function and long-term prognosis after a first Q wave myocardial infarction

OBJECTIVES The purpose of this study was to assess the prognostic significance of preinfarction angina after a first Q wave myocardial infarction. Patients with anterior or inferior myocardial infarction were compared. BACKGROUND The effect of preinfarction angina on prognosis after anterior and inferior myocardial infarction remains unclear. METHODS A total of 291 patients with a first Q wave anterior (n = 171) or inferior (n = 120) myocardial infarction were examined to assess the effect of preinfarction angina on short- and long-term prognosis. The relation between predischarge left ventriculographic findings and preinfarction angina was also examined. RESULTS The presence of preinfarction angina was associated with lower peak creatine kinase activity, a lower in-hospital incidence of sustained ventricular tachycardia and fibrillation and a lower incidence of pump failure and cardiac mortality in patients with either anterior or inferior infarction. Among patients with anterior infarction, preinfarction angina was associated with a lower incidence of cardiac rupture and less need for readmission for heart failure within 1 year after the onset of infarction. In this subgroup it was also associated with a higher ejection fraction, a smaller end-diastolic volume and a lower incidence of aneurysm formation noted on ventriculography during convalescence. In patients with inferior infarction, these variables did not differ significantly in the presence or absence of preinfarction angina. Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of development of ventricular aneurysm, late phase heart failure and 1-year cardiac mortality. CONCLUSIONS The presence of preinfarction angina has a favorable effect on infarct expansion and late phase left ventricular function, especially in patients with anterior myocardial infarction. The mechanisms responsible for this phenomenon are not known but may be secondary to limitations of infarct size through unidentified mechanisms other than collateralization (e.g., ischemic preconditioning).

Effect on short-term prognosis and left ventricular function of angina pectoris prior to first Q-wave anterior wall acute myocardial infarction

The prognostic significance of angina pectoris before the development of first Q-wave anterior wall acute myocardial infarction (AMI) was assessed in 153 patients. A total of 100 patients in this study had angina before Q-wave AMI, whereas 53 patients had no antecedent symptoms of angina. The presence of angina before AMI was associated with a lower incidence of complications including sustained ventricular tachycardia or fibrillation (7% vs 25%, p = 0.0022), pump failure (24% vs 47%, p = 0.0035), cardiac rupture (1% vs 17%, p = 0.0001), and a lower in-hospital mortality rate (11% vs 28%, p = 0.0067). The peak creatine phosphokinase activity was lower in patients with than without antecedent angina (1,727 +/- 1,238 vs 2,675 +/- 2,569 IU/liter, respectively, p = 0.023). There was no difference in the prevalence of multivessel coronary artery disease or the presence of collateral circulation between the 2 groups. Left ventriculography revealed a higher left ventricular ejection fraction (54 +/- 13% vs 46 +/- 11%, p = 0.034) and smaller left ventricular end-diastolic volumes (75 +/- 15 vs 86 +/- 18 ml/m2, p = 0.017) in patients with than without antecedent angina. These findings suggest that the presence of angina before AMI may be associated with a protective effect on left ventricular function during anterior wall AMI. Although the precise mechanisms underlying the beneficial effects are unknown, they may be related to the development of collateral channels or ischemic preconditioning.

Evaluation of combined valvular prolapse syndrome by two-dimensional echocardiography.

The patterns of aortic and tricuspid valve motion in 50 patients with mitral valve prolapse were analyzed by wide-angle, phased-array, two-dimensional echocardiography. Twelve patients (24%) had redundant aortic leaflets bulging into the left ventricular outflow tract during diastole. Eight of 12 patients had aortic regurgitation and seven of 12 had M-mode echocardiographic evidence of aortic valve prolapse. One patient underwent mitral and aortic valve replacement, and the excised valves revealed marked myxomatous degeneration. Eight of 15 patients undergoing contrast echocardiography had tricuspid regurgitation (systolic reflux of contrast material into the inferior vena cava persisting for more than 10 beats), and prolapse in the septal leaflet or the anterior leaflet or both. A similar tricuspid valve pattern was noted in three of seven patients without tricuspid regurgitation. Tricuspid valve prolapse was identified in 20 patients (40%). Nine patients (18%) had combined prolapse of the mitral, aortic and tricuspid valves. In five patients with middiastolic highpitched murmurs recorded along the left sternal border, tricuspid valve prolapse was demonstrated. In one of these patients, the presence of pulmonary regurgitation was confirmed by intracardiac phonocardiography. We conclude that two-dimensional echocardiography is useful for evaluating patients with combined valvular prolapse syndrome.

Early reduction of neurohumoral factors plays a key role in mediating the efficacy of β-blocker therapy for congestive heart failure

This study examined the role played by neurohumoral factors in mediating the effects of beta-blocker therapy for congestive heart failure. Fifteen patients with congestive heart failure underwent beta-blocker therapy. Plasma norepinephrine and alpha-atrial natriuretic peptide concentrations decreased 2 weeks after initiation of beta-blocker therapy. Decrease in plasma norepinephrine level persisted for 6 months. Lymphocyte beta-adrenoceptor density increased 2 weeks after therapy but was not increased 6 months later. Left ventricular ejection fraction was unchanged 2 weeks after therapy, but it increased 6 months after introduction of beta-blockers. Plasma norepinephrine level decreased 2 weeks after the therapy in the responders (increase in ejection fraction > 0.10) but not in the nonresponders. Thus early reduction of neurohumoral factor levels preceded the late improvement of left ventricular contractile function and may therefore be partly responsible for the efficacy of beta-blocker therapy for congestive heart failure.

A new approach to visualize the left main coronary artery using apical cross-sectional echocardiography

Patients undergoing coronary arteriography were studied to evaluate the feasibility of use of cross-sectional echocardiography to detect the left main coronary artery. Visualization of the left main coronary artery from the cardiac apex was attempted using a cranial transducer angulation. With this approach, the left main coronary artery was adequately visualized in 27 of 35 consecutive patients (77 percent) who were prospectively evaluated; in 12 of the 27 the bifurcation was clearly seen. In 26 of the 27 patients cross-sectional echocardiography correctly assessed the patency of the left main coronary artery as judged with coronary angiography. One patient had a false positive echocardiographic study; there were no false negative studies. A comparison of the short axis versus apical cross-sectional techniques in another group of 30 patients revealed the superiority of the apical approach in visualization of the left main coronary artery and its bifurcation; combined use of both techniques allowed for a 93 percent (rate of) success. Thus, apical cross-sectional echocardiography permits visualization of the left main coronary artery and its bifurcation and, therefore, has the potential for detecting left main coronary obstructive lesions.

Left ventricular ejection performance in mitral stenosis, and effects of successful percutaneous transvenous mitral commissurotomy

Impaired left ventricular ejection performance was reported in pure mitral stenosis. The speculative mechanisms included insufficient preload, increased wall stress, high right ventricular pressure and unknown myocardial factors, but no definitive mechanism has been established. Fifteen patients with tight mitral stenosis who underwent successful percutaneous transvenous mitral commissurotomy were studied to ascertain whether ejection performance would improve with sufficient blood filling. The indexes of preload (end-diastolic volume) and ejection performance (stroke volume, ejection fraction, and mean systolic and mean normalized ejection rates) were calculated angiographically before and immediately after mitral commissurotomy. Improved blood filling (the result of successful mitral commissurotomy) produced an increase in end-diastolic volume (mean +/- SD 99.0 +/- 30.2 to 112.1 +/- 30.1 ml/m2; p less than 0.05). All 4 indexes of ejection performance also improved. There was good correlation between end-diastolic and stroke volumes before intervention (stroke volume = 0.476 x end-diastolic volume + 16.77; r = 0.76), and the relation between them showed no change even after mitral commissurotomy. It is concluded that both left ventricular preload and ejection performance improved after successful percutaneous transvenous mitral commissurotomy. Insufficient preload could affect ejection performance in patients with tight mitral stenosis.

Increase in heart rate after radiofrequency catheter ablation is mediated by parasympathetic nervous withdrawal and related to site of ablation.

To assess the mechanism for the increased sinus rate after radiofrequency catheter ablation performed for atrioventricular nodal reentrant tachycardia (AVNRT), we studied heart rate variability before and after radiofrequency catheter ablation in 17 patients with AVNRT and in 38 patients with an accessory pathway. The accessory pathway was located at the left ventricular free wall, the right ventricular free wall, or the posterior interventricular septum. An increased sinus rate was observed in patients with AVNRT or with the accessory pathway at the posterior septum or left free wall after radiofrequency ablation. In these groups, high-frequency power, root mean square of successive difference and percent of adjacent cycles that were more than 50 ms apart, all of which are indices reflecting parasympathetic nervous activity, were decreased. The ratio of low-frequency to high-frequency power reflecting sympathovagal balance, was increased in patients with AVNRT or with an accessory pathway at the posterior septum or left free wall. Increases in sinus rate were correlated with decreases in high-frequency power, and percent of adjacent cycles more than 50 ms apart that the increase in heart rate was due to parasympathetic nervous withdrawal.

Acute myocardial infarction without warning: clinical characteristics and significance of preinfarction angina.

We investigated the clinical characteristics of acute myocardial infarction (AMI) not preceded by angina in 256 patients with first AMIs. Complications, including sustained ventricular tachycardia or ventricular fibrillation, pump failure and cardiac rupture, were more frequent in patients with AMI not preceded by angina (group 1, n = 92) than those preceded by angina (group 2, n = 164). The in-hospital mortality rate was higher in group 1 than in group 2. Poor preexisting collateral channels or lack of ischemic preconditioning may be responsible for the poorer outcome in group 1 patients.

A case of malignant lymphoma simulating acute myocardial infarction

A patient with malignant lymphoma suddenly collapsed, and ST segment elevation with complete atrioventricular block was observed on his electrocardiogram during an episode resembling acute myocardial infarction. Cardiac cineangiography revealed posterobasal asynergy of the left ventricle with no significant obstruction in the coronary arterial tree. Autopsy revealed diffuse invasion of the myocardium by lymphoma cells. Left ventricular wall motion was preserved even in the area of massive invasion; there was no true necrosis. Myocardial biopsy may be indicated in patients in whom there is a discrepancy between coronary pathoanatomy and wall motion abnormalities.