Hideyuki Shiotani

Comparison of left atrial size by freehand scanning three-dimensional echocardiography and two-dimensional echocardiography

AIMS As the left ventricular (LV) dimension is a poor indicator of LV volume, there are well-known limitations of left atrial (LA) antero-posterior dimensions as indicators of chamber size. LA volume has been shown to provide a more accurate assessment of LA size than LA dimension. To evaluate two-dimensional (2D)-derived LA volume in assessing LA size, we compared LA dimension and 2D LA volume with three-dimensional (3D)-derived LA volume. METHODS We performed transthoracic freehand scanning 3D echocardiography (3D EchoTech, Germany) using magnetic fields and a harmonic imaging system in 32 patients. We collected a series of LA tomograms by slowly tilting the probe (fan-like scanning) in the parasternal position. The 3D LA volume was calculated by using the multiplanar Simpsons method. The 2D LA volume was measured by using the modified biplane Simpsons rule. RESULTS LA antero-posterior dimensions and 2D volumes showed a significant positive correlation with 3D LA volumes. However, the correlation coefficient was significantly greater for the relationship between 2D LA volumes and 3D LA volumes than for that between LA dimensions and 3D LA volume. CONCLUSIONS The 2D LA volumes provide a more accurate measure of the true size of the LA and are more sensitive to changes in LA size.

Continuous positive nasal airway pressure decreases levels of serum amyloid A and improves autonomic function in obstructive sleep apnea syndrome

BACKGROUND Obstructive sleep apnea syndrome (OSAS) is associated with the pathogenesis of cardiovascular disease, and inflammation and autonomic dysfunction. We investigated levels of serum amyloid A (SAA), a marker of inflammation, as well as autonomic nervous activity and pulse wave velocity (PWV) before and after nasal continuous positive airway pressure (nCPAP) therapy in patients with obstructive sleep apnea. METHODS AND RESULTS We separated 116 patients who were diagnosed with OSAS by polysomnography according to the apnea hypopnea index (AHI) into the following groups: Group 1 without or with mild OSAS (AHI<20, n=35), Group 2 with moderate OSAS (20==40, n=46). Serum level of SAA (p<0.05), brachial-ankle PWV (p<0.05) and BP (p<0.005) were significantly higher in Group 3 than in Group 1. Autonomic nervous activity assessed by autoregressive spectral analysis of heart rate variability showed that high frequency (HF) power, an indicator of vagal activity, was decreased in Groups 2 and 3 (p<0.05) and that low frequency/HF, an indicator of sympathetic activity, was increased in Group 3 (p<0.05). After 3 months of nCPAP therapy in Group 3 (n=38), SAA (p<0.05), PWV (p<0.001) and BP (p<0.05) were significantly decreased. CONCLUSION Markers of inflammation and autonomic dysfunction are increased in patients with OSAS, and nCPAP might help to reduce these risk factors for cardiovascular diseases.

Effects of aerobic exercise on the circadian rhythm of heart rate and blood pressure.

Although the effects of aerobic exercise on resting heart rate, heart rate variability, and blood pressure have been investigated, there are scant data on the effects of aerobic exercise on the circadian rhythm of such cardiovascular parameters. In this study, we investigated the effects of aerobic exercise on the 24 h rhythm of heart rate and ambulatory blood pressure in the morning, when cardiovascular events are more common. Thirty-five healthy young subjects were randomized to control and aerobic exercise groups. Subjects in the latter group participated in their respective exercise program for two months, while those in the former group did not exercise. Twenty-four-hour electrocardiogram and ambulatory blood pressure monitoring data were obtained at baseline and at the end of the exercise intervention. The control group showed no changes, while the aerobic exercise group showed a significant decrease in heart rate (73.7 ± 6.6 bpm to 69.5 ± 5.1 bpm, p < 0.005) and sympathetic activity such as LF/HF ratio (2.0 ± 0.7 to 1.8 ± 0.6, p < 0.05) throughout the 24 h period, particularly in the daytime. The decrease in the heart rate was most prominent in the morning. However, heart rate and LF/HF ratio showed no statistical changes during the night. No significant changes were observed in blood pressure. These findings suggest aerobic exercise exerts beneficial effects on the circadian rhythm of heart rate, especially in the morning. (Author correspondence: hshio@kobe-u.ac.jp)

Resting123I-BMIPP scintigraphy in diagnosis of effort angina pectoris with reference to subsets of the disease

This study was undertaken to assess the diagnostic value of resting123I-BMIPP scintigraphy in patients with effort angina pectoris. One hundred and four patients underwent scintigraphic and angiographic examinations. The subsets of the patients were stable effort angina pectoris (stable type) in 27 cases, new onset of effort angina pectoris (new onset type) in 21 cases, and worsening effort angina pectoris (worsening type) in 35 cases. The remaining 21 cases were subjects without evidences of coronary artery disease (non-CAD).l23I-BMIPP was injected under resting and pain free condition, then data for single photon emission tomography (SPECT) were acquired. The positive regional123I-BMIPP defects in three coronary territories were visually judged on the tomographic images. The overall sensitivity to diagnose the patients was 62.6% (52/83) and the overall specificity to exclude non-CAD subjects was 95.2% (20/21). The detection rate in each subset of the disease was 48.1% (13/27) in stable type, 47.6% (10/21) in new onset type and 77.1% (27/35) in worsening type (p < 0.05 versus two other types). For detection of stenosed vessels, the overall sensitivity was 41.4% (56/148) and the overall specificity was 93.8% (152/164). The rate of detection of stenosed vessels was 31.7% (13/41) in stable type, 31.4% (11/35) in new onset type, and 55.6% (40/72) in worsening type (p < 0.05 versus two other types). Vessels with 75% stenosis were more sensitively detected in the worsening type (33.3%; 4/12) compared to the remaining two types (8.3%; 1/12) even though the difference was not significant. The resting123I-BMIPP scintigraphy was therefore valuable in diagnosing patients with effort angina pectoris and involved coronary arteries especially in the subset of patients with worsening type.

Torsade de Pointes in NIDDM with long QT intervals

Patients with diabetes are at an increased risk for sudden death (1). On the other hand, men with a long heart rate-adjusted QT interval (QTc) are at a higher risk for coronary heart disease and sudden death, even within the normal range of QTc in the general population (2). Sudden deaths in diabetic patients are attributed to circulatory failure and arrhythmia (3), the latter of which is difficult to diagnose. Recently, diabetic patients with prolonged QT intervals have been reported as prone to sudden death (4). We describe a diabetic man whose QTc lengthened substantially and who subsequently developed torsade de pointes, a fatal ventricular tachycardia (5).

Significance of detection of enterovirus RNA in myocardial tissues by reverse transcription-polymerase chain reaction

Enteroviruses are known to have association with human myocarditis and dilated cardiomyopathy (DCM). We screened biopsy specimens from patients with active myocarditis or DCM, and myocardial tissues from autopsy cases without cardiac diseases using polymerase chain reaction (PCR) gene amplification. Positive enteroviral signals were demonstrated from 4 of 5 patients with active myocarditis (80%), 7 of 42 patients with DCM(17%) and 3 of 27 autopsies (11%). Out of 7 PCR positive patients with DCM, 3 cases showed hypertrophy and disarray of cardiocytes, fibrosis in the interstitium, and a few inflammatory infiltrates. The remaining 4 cases with DCM and 3 PCR positive autopsy cases did riot exhibit histological findings compatible with those in myocarditis. Our results support the observations that enteroviruses are common aetiologic agents of myocarditis, and some cases of DCM. Our results also suggest the possibility that in some cases enteroviruses may persist in the myocardium without causing apparent pathological changes.

Diabetes Mellitus and Cardiomyopathy

In this report, cardiac abnormalities in 2 diabetic patients with a mutation in the mitochondrial tRNALeu(UUR)gene are described. The 2 patients exhibited left ventricular dilation and diffuse decreased wall motion. Cardiac catheterization studies revealed normal coronary angiography. In both patients, light microscopic examination of hematoxylin and eosin-stained sections revealed myocyte hypertrophy and perinuclear vacuolization and electron microscopy revealed an increase in the number and size of mitochondria and abnormal configuration of cristae. These findings suggest that mutations in mitochondrial DNA, such as an A→G mutation at position 3243, should be considered as a cause not only of diabetes mellitus but also of cardiac involvement in patients with diabetes mellitus. (Jpn Circ J 1998; 62: 309 - 310)

Fluorodeoxyglucose-Positron Emission Tomography Differentiating Thrombus From Tumor in the Left Ventricle

![Figure][1] In a patient with sarcomatoid carcinoma of left main bronchus, a computed tomography scan revealed an abnormal mass in the apex of the left ventricle (LV) (A) . Echocardiography showed a well-defined hyperechoic mass in the same region, wall motion was reduced in the apex and

A Comparison of Quantitative T2 Mapping on Cardiovascular Magnetic Resonance Imaging with Metaiodobenzylguanidine Scintigraphy and Left Ventricular Functional Recovery in Dilated Cardiomyopathy: A Retrospective Pilot Study

OBJECTIVE Metaiodobenzylguanidine (MIBG) scintigraphy is used to assess heart failure (HF) severity and to predict cardiac functional recovery. Cardiovascular magnetic resonance (CMR) imaging has recently been used to diagnosis HF. We evaluated CMR T2 mapping and MIBG scintigraphy in dilated cardiomyopathy (DCM) patients. METHODS Consecutively, 22 DCM patients [aged 56.8 ± 13.4 years; 6 women and 16 men; left ventricular ejection fraction (LVEF), 31.9 ± 10.7%] who underwent T2 mapping and MIBG scintigraphy were retrospectively evaluated. Echocardiography results were recorded at baseline and the 6-month follow-up. Patients with an increased LVEF ≥15% between the 2 measures were considered to be responders. We measured each patients T2 values and MIBG indices [the heart-to-mediastinum ratio (H/M) in the early phase, H/M in the delayed phase, and the washout rate (WOR)] at baseline. We compared these values between the 12 responders and 10 non-responders. RESULTS The mean T2 value for all patients was 64.5 ± 6.6 ms. The mean values of early H/M, delayed H/M, and WOR were 2.06 ± 0.25, 1.94 ± 0.35, and 43.5 ± 11.8%, respectively. The T2 values were found to correlate with MIBG indices (p<0.05 for all) and were lower in the responders than non-responders (61.4 vs. 68.1 ms, p=0.013). MIBG indices were not significantly different. CONCLUSION Our study shows that the T2 values correlated with the MIBG indices and were increased in non-responders. T2 mapping may be useful in assessing the cardiac function and functional recovery in DCM patients.

Predicting the response to cardiac resynchronization therapy using 99mTc-tetrofosmin myocardial scintigraphy in patients with drug-refractory heart failure: additional value of the washout of 99mTc-tetrofosmin.

ObjectiveA lack of response to cardiac resynchronization therapy (CRT) has been reported in 20–40% of heart failure patients with left ventricular (LV) dyssynchrony who underwent treatment based on the established guidelines. The study aimed to investigate the relationship between 99mTc-tetrofosmin (99mTc-TF) myocardial scintigraphy and the response to CRT. Patients and methodsTwenty-one patients with drug-refractory heart failure who underwent CRT were evaluated. All patients underwent 99mTc-TF myocardial scintigraphy before and after CRT. Single-photon emission computed tomography images of 99mTc-TF were acquired at 30 min and 3 h after injection and were used to determine the total defect score (TDS) and washout score (WOS). The change in the LV volume and ejection fraction (&Dgr;LVEF) and relative reduction in left ventricular end-systolic volume (%&Dgr;LVESV) were calculated as an index of LV functional recovery after CRT. Response to CRT was considered to have occurred when &Dgr;LVEF was greater than 15% or when &Dgr;LVEF was greater than 5% and %&Dgr;LVESV was greater than 15%. ResultsSignificant differences were observed between the patients who responded to CRT (the responder group, 13 patients) and the nonresponder group (eight patients) for both early and delayed TDS and WOS (P<0.05). Moreover, there was a good correlation between early TDS before CRT and both &Dgr;LVEF and %&Dgr;LVESV (P<0.01) and an excellent correlation between WOS before CRT and both &Dgr;LVEF and %&Dgr;LVESV (P<0.01). ConclusionEvaluating the washout of 99mTc-TF in addition to myocardial perfusion before CRT using 99mTc-TF myocardial scintigraphy might be useful in drug-refractory heart failure patients.