A case of acute myocardial infarction caused by left main trunk disease with dilated cardiomyopathy.

A case of acute myocardial infarction caused by left main trunk disease with dilated cardiomyopathy is presented. Cardiac MRI findings may suggest the etiology of left ventricular dysfunction in this case is idiopathic dilated cardiomyopathy, which associated with acute myocardial infarction caused by left main trunk disease.

Bilateral giant coronary aneurysms diagnosed non-invasively by dynamic magnetic resonance imaging.

Giant coronary aneurysms are sometimes misdiagnosed as cardiac tumors when they are filled with thrombus. In this case, dynamic magnetic resonance imaging revealed the coronary artery and cardiac mass, and was the most useful tool for diagnosis of giant coronary aneurysms non-invasively.

Effective cardiac resynchronization after Dor procedure and mitral annuloplasty.

Endoventricular circular patch plasty (Dor ventriculoplasty) is an effective strategy for severely impaired left ventricular function due to ischemic cardiomyopathy. Cardiac resynchronization therapy improves cardiac function in patients with severe congestive heart failure and an intraventricular conduction delay. The present case demonstrates the efficacy of adding cardiac resynchronization to Dor ventriculoplasty and mitral annuloplasty in a patient with severely impaired left ventricular function and an intraventricular conduction delay.

Intravascular hemolysis in aortic stenosis.

A 67-year-old woman with rheumatic aortic stenosis for 20 years was admitted to our hospital. Although she had no overt symptoms, she had severe aortic valve stenosis with a transvalvular pressure gradient of more than 150 mmHg. She had also been suffering from anemia and mild chronic renal failure. A peripheral blood smear showed numerous fragmented erythrocytes. Hemoglobin was 8.4 g/dl, lactate dehydrogenase was 316 IU/l, haptoglobin was less than 7.3 mg/dl, and hemosiderinuria was evident. We diagnosed intravascular hemolysis related to aortic stenosis. After we performed an aortic valve replacement, fragmentation on the peripheral blood smear dramatically disappeared.

Correlation between late gadolinium enhancement and diastolic function in hypertrophic cardiomyopathy assessed by magnetic resonance imaging.

BACKGROUND: Diastolic dysfunction is common in patients with overt hypertrophic cardiomyopathy (HCM). Steady-state cine magnetic resonance imaging (MRI) enables measurement of the diastolic function of the left ventricle (LV), and late gadolinium enhanced MRI can delineate the presence and extent of fibrosis in HCM. The purpose of this study was to determine the relationship between the extent of myocardial fibrosis demonstrated by late gadolinium-enhanced MRI and diastolic dysfunction. METHODS AND RESULTS: Seventeen patients (13 men, mean age 57.7+/-9.8 years) with HCM were studied. The severity index of late gadolinium enhancement was determined by scoring the extent of enhanced tissue in 30 myocardial segments. The peak filling rate (PFR), LV ejection fraction and LV mass were determined by cine MRI. Contrast-enhanced MRI demonstrated late gadolinium enhancement in 97 of 510 segments (19%) and 13 of the 17 patients (77%). The severity index of late gadolinium enhancement demonstrated a significant negative correlation with PFR (r= -0.86, p<0.01) and with the LV ejection fraction (r= -0.59, p<0.05). No significant correlation was observed between the severity index of late gadolinium enhancement and LV mass (r=0.23, p=0.30). CONCLUSION: The extent of myocardial fibrosis revealed by late gadolinium-enhanced MRI has a strong relationship to diastolic dysfunction in patients with HCM.

Newly diagnosed acute aortic dissection: characteristics, treatment modifications, and outcomes.

The objective of the present study was to examine cases of acute aortic dissection in order to analyze the clinical and diagnostic findings, and to summarize their treatment modalities, as well as their hospital outcomes. Between July 1998 and June 1999, we prospectively studied patients who were newly diagnosed as having acute aortic dissection at 25 hospitals in Mie prefecture. These cases were examined for their demographics, the characteristics of the clinical findings, diagnostic methods, treatment modalities according to the type of aortic dissection, and the early morbidity and mortality of the hospital outcomes. Of 66 newly diagnosed aortic dissections (43 males), 30 were type A and 36 were type B. Seventy-six percent of the cases arrived at a medical facility within 6 hours from the onset of symptoms. Frequent initial symptoms and clinical findings were pain in 95.5%, cardiac arrest and/or hypotension in 21%, pericardial effusion in 29%, pleural effusion in 25%, and neurological signs in 30%. Twenty-one patients underwent surgical repair, 36 were treated medically, and 5 underwent endovascular stenting. Overall early mortality was 12.1%, which included 2 DOA. Fifty percent of these deaths occurred within 48 hours, and 63% by 72 hours of the initial event. In spite of the relatively rare incidence of acute aortic dissection in our study, the calculated incidence was 4.0/100,000/year. The overall mortality rate was relatively low compared to the figures reported in the literature, suggesting the earliest possible diagnosis and timely intervention are critically important to attain successful outcomes.

Noninfarcted myocardium: correlation between dynamic first-pass contrast-enhanced myocardial MR imaging and quantitative coronary angiography.

PURPOSE: To determine the accuracy of first-pass contrast material-enhanced stress myocardial magnetic resonance (MR) imaging for depiction of myocardial ischemia in patients without myocardial infarction. MATERIALS AND METHODS: First-pass contrast-enhanced MR images of the entire left ventricle were acquired in 104 patients at rest and during dipyridamole-induced stress by using an interleaved notched saturation technique. Coronary angiography was performed in all patients, and stress perfusion single photon emission computed tomography (SPECT) was performed in 69 patients. Receiver operating characteristic curve analysis was performed to compare the diagnostic accuracies of first-pass contrast-enhanced stress MR imaging and stress SPECT, with coronary angiography as the reference standard. RESULTS: The overall sensitivity of MR imaging for depicting at least one coronary artery with significant stenosis was 90% (69 of 77 patients). The sensitivities of MR imaging for depiction of single-, double-, and triple-vessel stenoses were 85% (33 of 39 patients), 96% (22 of 23 patients), and 100% (15 of 15 patients), respectively. The specificity of MR imaging for identification of patients with significant coronary artery stenoses was 85% (23 of 27 patients). The areas under the receiver operating characteristic curve for detection of significant stenosis in individual coronary arteries were 0.888 (observer 1) and 0.911 (observer 2) for MR imaging and 0.707 (observer 1, P <.001) and 0.750 (observer 2, P <.001) for SPECT. CONCLUSION: In patients without myocardial infarction, stress enhancement at dynamic MR imaging correlates more closely with quantitative coronary angiography results than does stress enhancement at SPECT.

Prediction of regional functional recovery after acute myocardial infarction with low dose dobutamine stress cine MR imaging and contrast enhanced MR imaging.

PURPOSE: Previous studies demonstrated that low-dose dobutamine stress cine magnetic resonance imaging (MRI) and delayed contrast-enhanced MRI can provide assessments of myocardial viability. The purpose of this study was to evaluate the comparative diagnostic values of dobutamine cine MRI and delayed contrast-enhanced MRI for predicting functional recovery of myocardial contraction in patients with acute reperfused myocardial infarction. METHODS: Twenty-three patients with myocardial infarction after percutaneous coronary interventions were studied. All patients underwent steady-state cine MRI covering the entire left ventricle at rest and during low-dose dobutamine stress (10 micrograms/kg/min). Delayed contrast-enhanced MR images were acquired to determine transmural extent of hyperenhancement. Second cine MR images in the resting state were obtained 3 to 11 months after revascularization. RESULTS: On the first cine MR images in the resting state, 278 (20%) of 1380 segments demonstrated abnormal, regional contraction (systolic wall thickening < 40%). Of the 175 segments showing functional recovery on the following cine MRI, 156 (89%) segments were recognized as reversible by dobutamine cine MRI and 146 (83%) segments by delayed contrast-enhanced MRI. The sensitivity, specificity, and accuracy of dobutamine stress cine MRI was 89%, 80%, and 86%, respectively. These values of contrast-enhanced MRI were 83%, 72%, and 79%, respectively. The area under the receiver operating curve (ROC) was 0.87 by dobutamine cine MRI and 0.78 by delayed contrast-enhanced MRI (p < 0.05). CONCLUSIONS: The current results using quantitative segmental analysis indicated that low-dose dobutamine stress cine MRI can predict recovery of myocardial contractility with significantly higher diagnostic performance in comparison with contrast-enhanced MRI in patients with myocardial infarction who underwent revascularization.

A case of inverted left atrial appendage mimicking a tumor.

We report a rare case of an inverted left atrial appendage without prior cardiac surgery. A left atrial mass was incidentally found during routine echocardiography in a 19-year-old man with mitral valve prolapse. Echocardiography revealed a hyperechoic mass in the left atrium, and a neoplastic lesion could not be excluded. On magnetic resonance imaging (MRI), this mass consisted of fat tissue that showed continuation to epicardial fat, indicating an inverted left atrial appendage mimicking a tumor in the left atrium. When a mass in the left atrium is observed on echocardiography, there are several differential diagnoses, including thrombus, vegetation, and intra-atrial neoplasms such as myxomas. Recently, several studies reported cases with inverted left atrial appendages mimicking tumors in patients after cardiac operations. We present a case of inverted left atrial appendage without any prior cardiac surgery. Cardiac MRI was highly useful to obtain the final diagnosis of inverted left atrial appendage.

Thallium-201 SPECT and low-dose dobutamine stress cine MRI for predicting functional recovery of regional myocardial contraction in patients with myocardial infarction.

OBJECTIVES: The purpose of this study was to compare the diagnostic performances of Tl-201 single photon emission computed tomography (SPECT) and dobutamine stress cine magnetic resonance imaging (MRI) for predicting functional recovery of regional myocardial contraction in patients after myocardial infarction. METHODS: Twenty patients underwent Tl-201 SPECT and MRI 3-4 weeks after onset of myocardial infarction. Cine MR images were acquired in the resting state and during dobutamine stress. Tl-201 uptake and systolic wall thickening (SWT) on cine MRI were analyzed on short-axis images by using a 14-segment model. Follow-up cine MR images were obtained 187.1+/-33.5 days after onset. RESULTS: The averaged Tl-201 uptake in 54 segments with impaired SWT was 47%+/-20%, being significantly lower than that in 226 segments with preserved SWT (75%+/-18%; p<0.0001). The sensitivity, specificity, and accuracy of dobutamine MRI and Tl-201 SPECT for predicting preserved SWT after 6 months were 89% vs. 80%, not significant (NS); 89% vs. 72%, p<0.01; and 89% vs. 79%, NS, respectively. In the anterior wall and apex, the sensitivity and specificity of SPECT were not significantly different from those of MRI. In the inferior wall and posterolateral wall, however, the specificity of SPECT was substantially lower than that of MRI (53% vs. 88%, p<0.001), resulting in significantly lower accuracy (75% vs. 90%, p<0.01). CONCLUSIONS: Both SPECT and dobutamine MRI showed excellent sensitivity for predicting myocardial viability in all left ventricular segments. Decreased specificity of SPECT in the inferior and posterolateral segments resulted in lower overall specificity in comparison with dobutamine MRI.