Yoshie Harimura

Early repolarization is an independent predictor of occurrences of ventricular fibrillation in the very early phase of acute myocardial infarction.

Background—Recent evidence has linked early repolarization (ER) to idiopathic ventricular fibrillation (VF) in patients without structural heart disease. However, no studies have clarified whether or not there is an association between ER and the VF occurrences after the onset of an acute myocardial infarction (AMI). Methods and Results—This study retrospectively included 220 consecutive patients with an AMI (57 female; mean age, 69 ± 11 years) in whom the 12-lead ECGs before the AMI onset could be evaluated. The patients were classified on the basis of a VF occurrence within 48 hours after the AMI onset. Early repolarization was defined as an elevation of the QRS-ST junction of >0.1 mV from baseline in at least 2 inferior or lateral leads, manifested as QRS slurring or notching. Twenty-one (10%) patients had a VF occurrence within 48 hours of the AMI onset. A multivariate analysis revealed that ER (odds ratio [OR], 7.31; 95% confidence interval [CI], 2.21–24.14; P<0.01), a time from the onset to admission of <180 minutes (OR, 3.77; 95% CI, 1.13–12.59; P<0.05), and a Killip class greater than I (OR, 13.60; 95% CI, 3.43–53.99; P<0.001) were independent predictors of VF occurrences. As features of the ER pattern, a J-point elevation in the inferior leads, greater magnitude of the J-point elevation, notched morphology of the ER, and ER with a horizontal/descending ST segment, all were significantly associated with a VF occurrence. Conclusions—The presence of ER increased the risk of VF occurrences within 48 hours after the AMI onset.

Analysis of the Left Atrial Appendage by Three-Dimensional Transesophageal Echocardiography

This study was designed to determine the ability and reliability of 3-dimensional (3D) transesophageal echocardiography (TEE) to assess the geometry and size of the left atrial appendage (LAA). Three-dimensional TEE may allow more accurate assessment of, and provide additional information on, LAA morphology compared to 2-dimensional TEE. Validation studies for LAA morphology data derived from 3D TEE were performed using 10 isolated porcine LAA specimens. Of 107 enrolled patients, 55 patients were in sinus rhythm (normal sinus rhythm), in whom 3D transesophageal echocardiographic images were obtained from full-volume mode imaging, and in 52 patients with atrial fibrillation, zoom-mode imaging was used. LAA orifice area, depth, and volume and the number of LAA lobes were assessed on reconstructed 3D imaging. Left atrial volume was calculated using 2-dimensional echocardiographic imaging. In experimental studies, excellent correlations (r >0.90, p <0.001) between the measurements by full-volume or zoom-mode imaging and reference data were observed in all parameters. The mean LAA orifice long diameter was 29.7 +/- 7.4 mm, the mean short diameter was 20.6 +/- 5.9 mm, the mean orifice area was 5.1 +/- 2.5 cm(2), the mean LAA depth was 38.5 +/- 8.2 mm, and the mean volume was 9.2 +/- 5.6 ml. The most frequent number of LAA lobes was 2 (n = 52), followed by 3 (n = 28), 1 (n = 18), and 4 (n = 3). Left atrial volume was weakly correlated with LAA orifice long diameter (r = 0.33, p = 0.001), short diameter (r = 0.40, p <0.001), area (r = 0.39, p <0.001), LAA depth (r = 0.21, p = 0.03), and volume (r = 0.36, p = 0.001). In conclusion, 3D TEE is a reliable modality to evaluate LAA geometry and provides detailed information to quantify varied LAA characteristics.

Early Repolarization Increases the Occurrence of Sustained Ventricular Tachyarrhythmias and Sudden Death in the Chronic Phase of an Acute Myocardial Infarction

Background—We recently showed that the presence of early repolarization (ER) increases the risk of ventricular fibrillation occurrences in the early phase of acute myocardial infarction (AMI). This study aimed to clarify whether an association exists between ER and occurrences of ventricular tachyarrhythmias or sudden death in the chronic phase of AMI. Methods and Results—This study retrospectively enrolled 1131 patients (67±12 years; 862 men) with AMIs surviving 14 days post-AMI. The primary end point was the occurrence of sustained ventricular tachyarrhythmias or sudden death >14 days after the AMI onset. We evaluated the presence of ER from the predischarge ECG (mean 10±3 days post-AMI). ER was defined as an elevation of the terminal portion of the QRS complex of >0.1 mV in inferior or lateral leads. After a median follow-up of 26.2 months, 26 patients had an episode of ventricular tachyarrhythmias or sudden death. A multivariable Cox regression analysis revealed the presence of ER (hazard ratio, 5.37; 95% confidence interval, 2.27–12.69; P<0.001), Killip class on admission of >I (hazard ratio, 2.75; 95% confidence interval, 1.24–6.07; P=0.013), and a left ventricular ejection fraction of <35% (hazard ratio, 11.83; 95% confidence interval, 5.16–27.13; P<0.001) were significantly associated with event occurrences. As features of the ER pattern, ER in the inferior leads, high-amplitude ER, a notched morphology, and ER without ST-segment elevation were associated with an increased risk of event occurrences. Conclusions—ER observed at a mean of 10 days post-AMI may be a marker for a subsequent risk of ventricular tachyarrhythmias or sudden death.

Utility of Real-Time 3-Dimensional Echocardiography and Magnetic Resonance Imaging for Evaluation of Danon Disease

A 21-year-old man was admitted to the hospital with exertional dyspnea. At the age of 14, he was diagnosed with Danon disease by genetic analysis (a 2–base-pair deletion at positions 288 and 289 in exon 3 was identified in the lysosome-associated membrane protein-2 [LAMP2] gene of the patient, which led to a frameshift and resulted in a premature stop codon). A chest radiograph demonstrated moderate cardiomegaly (cardiothoracic ratio of 58%). The ECG exhibited normal sinus rhythm, wide and bifid P waves with a duration of 170 ms, complete left bundle-branch block with a QRS duration of 200 ms, and a leftward axis (−2°; Figure 1). Figure 1. Twelve-lead ECGs. Echocardiography revealed left ventricular (LV) dilatation with an end-diastolic internal dimension of 60 mm and diffusely hypokinetic LV wall motion with fractional shortening of 8% (Figure 2; Movie I of the online-only Data Supplement). …

Effect of season on peripheral resistance to localised cold stress

This study was carried out to determine the effect that seasonal changes have on the effect of localised cold stress on peripheral temperatures using the foot immersion method with a cold water bath. The subjects were six males and four females. The data were obtained in April, July, October and January. Skin temperature of the right index finger, the forehead, the arm, the cheek, the second toe and the instep were measured before, during and after the immersion of the feet in water at 15°C for 10 mins, as well as oxygen consumption before immersion of the feet.The average finger temperature was highest during foot immersion in the summer, next highest in the winter, then spring, and the lowest during foot immersion in the autumn. The finger temperatures during the pre-immersion period in the autumn tended to be lower than in other seasons. The finger temperatures during the pre-immersion period affected the temperature change of the finger during the immersion period. The rate of increase of the toe temperature and the foot temperature during post-immersion in the summer and the spring were greater than those in the autumn and winter. Oxygen consumption during the pre-immersion period in the autumn was significantly lower than in the other seasons (p<0.001 or 0.010). Cooling the feet caused no significant changes in the temperatures the cheek, forehead or forearm. The cheek temperature in the summer and autumn was cooler than corresponding temperatures taken in the winter and spring.

Optimal cut-off value of reverse remodeling to predict long-term outcome after cardiac resynchronization therapy in patients with ischemic cardiomyopathy

BACKGROUND Whether the optimal cut-off value of left ventricular (LV) reverse remodeling is different in patients with ischemic cardiomyopathy (ICM) vs. non-ischemic cardiomyopathy (NICM) is unclear. This study aimed to clarify this value in patients with ICM and NICM. METHODS AND RESULTS LV reverse remodeling was defined as a reduction in LV end-systolic volume (LVESV) at 6 months after cardiac resynchronization therapy (CRT). The clinical endpoint was the combination of cardiac death and first hospitalization for worsening heart failure. Ninety-one of 372 patients had ICM. Event-free survival rates did not differ between ICM and NICM groups (66.8% vs. 78.9%; p=0.12). Receiver operating characteristics analysis revealed a 9% reduction in ESV as the optimal cut-off value to predict the composite endpoint in patients with ICM and a 15% reduction in patients with NICM. Multivariate analysis revealed that reductions in ESV of ≥15% and ≥9% were independent predictors of the composite endpoint, as were left bundle branch block (LBBB) and B-type natriuretic peptide (BNP) at 6 months after CRT. In combination with LBBB and BNP, reduction in ESV ≥9% had a higher, but not significant, C-statistics value than ESV ≥15% (0.854, 95% CI 0.729-0.940 vs. 0.801, 95% CI 0.702-0.908, p=0.07). CONCLUSION The optimal cut-off value of a reduction in LVESV was lower in patients with ICM than in patients with NICM.

Response to Letter Regarding Article, “Early Repolarization Is an Independent Predictor of Occurrences of Ventricular Fibrillation in the Very Early Phase of Acute Myocardial Infarctions”

We thank Drs Hayashi and Horie for their comments with regard to our recently published article.1 Previous reports demonstrated that cardiovascular drugs and heart rate can potentially alter the presence early repolarization.2–4 The prescribed medications and heart rate …