Eisei Kachi

Sequential changes in cardiac structure and function in patients with Duchenne type muscular dystrophy : A two-dimensional echocardiographic study

BACKGROUND Most patients with progressive muscular dystrophy of the Duchenne type (DMD) die of respiratory failure at approximately 20 years of age. However, some patients with DMD die of heart failure in relatively short periods of time. We investigated the long-term progression of cardiac impairment in patients with DMD by two-dimensional echocardiography. METHODS We monitored 74 patients for 4 years with two-dimensional echocardiography. Patients were classified into four groups according to the 8-grade Swinyard-Dever system. We also evaluated the echocardiographic features of 22 other patients with DMD with studies performed within 1 year before their deaths. RESULTS During the 4-year follow-up the left ventricle expanded, and regional left ventricular wall motion abnormalities developed in the posterior wall and apex. Almost all patients had myocardial dysfunction that progressed in parallel with their Swinyard-Dever stage. However, in a few patients who died of congestive heart failure, left ventricular dilation and circumferential left ventricular wall motion were severely impaired. CONCLUSIONS Myocardial impairment is accelerated in patients with DMD who died of heart failure. Two-dimensional echocardiography is a useful tool for the early diagnosis of left ventricular dysfunction and provides useful information for the treatment of patients with DMD.

Circadian rhythm and variability of heart rate in Duchenne-type progressive muscular dystrophy

Using 24-hour Holter monitoring and time domain and power spectral measurements, we evaluated the variability of the heart rate and its circadian rhythm in 55 male patients with Duchenne-type progressive muscular dystrophy (DMD) to characterize their autonomic function versus findings in 20 normal controls. Comparisons were also made in patients with mild, moderate, and severe stages of DMD. The percent difference between successive RR intervals that exceeded 50 ms, a measure of parasympathetic tone, was significantly lower even in patients with early stage of DMD than in controls (p < 0.01). This trend became marked with disease progression. Power in the high-frequency (HF) range (0.15 to 0.40 Hz), a measure of parasympathetic tone, was lower (p < 0.01), and the ratio of the power in the low-frequency (LF) range (0.04 to 0.15 Hz) and that of HF range (LF/HF ratio), a measure of sympathetic tone, was higher in DMD patients versus controls (p < 0.01). This trend was also marked with disease progression. Patients with mild or moderate disease had a slight circadian alteration in HF and LF/HF ratio. Patients with severe disease had virtually no circadian rhythm in HF. Their LF/HF ratio was higher at night (p < 0.01), lower in the morning (p < 0.01), and still lower during the day (p < 0.01), the opposite of control findings. The autonomic abnormalities in DMD were thus characterized by a significant increase in sympathetic activity and a significant decrease in parasympathetic activity. Thus, heart rate variability and circadian rhythm were useful in assessing autonomic dysfunction in DMD.

ST-segment elevation in right precordial leads implies depressed right ventricular function after acute inferior myocardial infarction

BACKGROUND The prognosis of acute inferior myocardial infarction is worse when it is complicated by right ventricular infarction. ST elevation in the right precordial leads is one of the reliable methods for detecting acute right ventricular infarction. The purpose of the study was to examine the relation between ST elevation in the right precordial electrocardiographic leads during acute inferior infarction and the severity of right ventricular systolic dysfunction. METHODS This study analyzed the relation between ST elevation > or = 0.1 mV in V4R and the severity of right ventricular systolic dysfunction in 43 consecutive patients (men/women: 35/8; average age 62+/-9 years) with acute inferior myocardial infarction with a rapid-response Swan-Ganz catheter to measure the right ventricular ejection fraction (RVEF). RESULTS RVEF was significantly lower in patients with ST elevation (n = 18) than in those without (n = 25) (33%+/-6% vs 40%+/-9%, p = 0.010). If the infarct-related lesion was located in the proximal right coronary artery, RVEF tended to be lower than if the lesion was located in the distal right coronary artery or the left circumflex coronary artery (33%+/-10% vs 37%+/-9% vs 42%+/-9%, p = 0.101). Logistic regression analysis demonstrated that ST elevation in V4R was the only independent predictor of depressed RVEF (odds ratio = 5.31, 95% confidence interval = 1.28 to 22.1, p = 0.022). CONCLUSION ST elevation in lead V4R during acute inferior myocardial infarction predicts right ventricular systolic dysfunction.

Directed Proximal Magnetic Resonance Coronary Angiography Compared With Conventional Contrast Coronary Angiography

Magnetic resonance coronary angiography in 36 patients with proximal 1-vessel disease within 1 week of contrast coronary angiography was performed and the time required to complete the study was 13.4 +/- 4.2 min 13.2 +/- 8.1 minutes for the right and left coronary arteries, respectively. The sensitivity, specificity, positive and negative predictive values, and accuracy of magnetic resonance coronary angiography were 100% for right cronary artery disease, and 83%, 98%, 94%, 94%, and 94%, respectively, for left coronary artery disease.

Cardiac rupture and admission electrocardiography in acute anterior myocardial infarction: Implication of ST elevation in aVL

This study determines the usefulness of electrocardiography in the emergency room for assessing the risk of cardiac rupture after acute anterior myocardial infarction (MI). The presence of ST segment elevation on the admission 12-lead electrocardiography was evaluated in 325 consecutive anterior MI patients. A forward-stepwise logistic regression analysis for cardiac rupture was performed with the covariates of age, gender, hypertension, history of MI, reperfusion therapy by coronary angioplasty, and ST segment elevations in leads I, aVL, V1-V6. Cardiac rupture occurred in 16 patients, including 7 with left ventricular free wall rupture (FWR) and 9 with ventricular septal perforation (VSP). For FWR, ST elevation in lead aVL was the only independent predictor (odds ratio = 12.1, P = .0215). For VSP, female gender (odds ratio = 5.32, P = .0201) was the independent predictor. In conclusion, in patients with acute anterior MI, ST segment elevation in lead aVL on the admission electrocardiography is a significant risk factor for left ventricular FWR.

Asynergy of the Noninfarcted Left Ventricular Inferior Wall in Anterior Wall Acute Myocardial Infarction Secondary to Isolated Occlusion of the Left Anterior Descending Artery

There are patients in whom left ventricular (LV) wall motion decreases in the noninfarcted region and LV systolic function declines globally despite the presence of a localized myocardial infarct attributable to narrowing or occlusion of a single coronary artery. This study examines angiographic characteristics of patients with chronic hypokinesia of noninfarcted myocardium after anterior wall acute myocardial infarction (AMI) due to narrowing of a single coronary artery, namely, the left anterior descending (LAD) artery. The LV ejection fraction, abnormalities in the motion of the noninfarcted LV inferior wall (SD/chord value by Sheehans technique), the angiographic characteristics of the infarct-related coronary artery, the effect of acute reperfusion therapy, and presence of coronary risk factors were examined in 85 consecutive patients. The SD/chord value in the noninfarcted region showed a positive correlation with the LV ejection fraction (r = 0.505, p <0.0001). By multivariate analysis, hypertension (odds ratio = 0.53, 95% confidence interval [CI] 0.36 to 0.80), an infarct-related narrowing proximal to the origin of the first diagonal branch (odds ratio = 0.56, 95% CI 0.38 to 0.84), and patency of the infarct-related lesion during AMI (odds ratio = 1.56, 95% CI 1.03 to 2.30) were independent predictors of wall motion in the noninfarct region. In some patients with single-vessel anterior wall AMI, the motion of the noninfarcted inferior LV wall decreases during the chronic stage and cardiac function declines severely. In most of these patients, the infarct-related narrowing or occlusion is proximal to the origin of the first diagonal branch of the LAD artery.

ST-Segment Elevation in Leads I and aVL Predicts Short-Term Prognosis in Acute Anterior Wall Myocardial Infarction

Our study demonstrates that ST-segment elevation in both leads I and aVL noted on admission for an anterior acute myocardial infarction does portend a worse short-term survival. Independent predictors of short-term prognosis in an anterior acute myocardial infarction include ST elevation in both leads I and aVL, advanced age, female gender, left ventricular failure, and malignant arrhythmias.

Transition from classic aortic dissection to aortic intramural hemorrhage--a case report.

A 64-year-old man was hospitalized with chief complaints of chest and back pain. A diagnosis of Stanford type A aortic dissection with a false lumen extending from the ascending to the descending aorta was made based on the results of computed tomog raphy (CT). A CT obtained the following day showed resolution of the false lumen and increased brightness of the aortic wall, typical of aortic dissection with intramural hemor rhage. Although previous studies have described a gradual transition from aortic intra mural hemorrhage to aortic dissection with a false lumen, there are no reports of the transition from an aortic dissection with a false lumen to the intramural hemorrhage type of aortic dissection. This patient is of interest when considering the pathogenesis of aortic dissection with intramural hemorrhage and the relationship between the intra mural hemorrhage and false-lumen types of aortic dissection.