Back somersault-induced atrioventricular nodal reentrant tachycardia - A case of a 15-year-old promising gymnast.

A male 15-year-old promising gymnast suffered palpitations, which emerged only after landing a round-off back somersault. The performance induced an attack of regular narrow QRS complex tachycardia that was highly reproducible. Not a single element of the performance, but a whole sequence of round-off back somersault was required to induce the attack. An electrophysiologic study revealed an intra-nodal dual pathway causing atrioventricular nodal reentrant tachycardia (AVNRT). A complication of a tiny atrial septal defect (ASD) was incidentally detected, thus we initially suspected a causal relation of ASD as the platypnea-orthodeoxia syndrome. However, it was denied as the major mechanism of attack because of a very faint shunt flow and no-induction of hypoxemia during a round-off back somersault. The major triggering mechanisms of a whole sequence of round-off back somersaults were speculated to be related to transient atrial overload and autonomic imbalance induced by a swift postural-axial change together with an intense Valsalva maneuver with the maximal level of breath holding. The AVNRT attack was successfully treated by radiofrequency catheter ablation and has never recurred even by a whole sequence of round-off back somersaults. Currently he is a healthy and active gymnast with no symptoms. .

Cerebral Microbleeds Remain for Nine Years: A Prospective Study with Yearly Magnetic Resonance Imaging.

BACKGROUND: Cerebral microbleeds (CMBs) are refined neuroimaging findings detected on T2*-weighted gradient echo (GRE) magnetic resonance imaging (MRI) and are widely accepted as an important marker of the vulnerability of cerebral small vessels. It is necessary to further clarify the natural history of CMBs by a longitudinal study. This study aimed to reveal the natural history of CMBs and find a better way to track CMBs by a prospective long-term observation. METHODS: We performed yearly brain MRI assessments for 7 or more years in 8 nonvalvular atrial fibrillation Japanese outpatients with CMBs detected in the baseline MRI. We began to use a 3.0T MRI scanner from 2012 as well. RESULTS: We followed up 3 patients for 9 years, 2 for 8 years, and 3 for 7 years. In all patients, the CMBs at baseline did not disappear during the follow-up period. Importantly, the CMB in 1 patient seemed to disappear during the sixth imaging using 1.5T T2*-weighted GRE but was detected again during the seventh imaging with 3.0T susceptibility weighted imaging and ninth imaging with 3.0T T2* GRE. Moreover, in a patient implanted with a pacemaker, which is only applicable for 1.5T MRI at present, the CMB seemed to disappear and appeared once again with a 1.5T T2*-weighted GRE at a slice thickness of 2.5 mm instead of 5 mm. CONCLUSIONS: From this prospective study, we obtained 2 absolutely new findings that CMBs remained for as long as 9 years and a high-field or thin-slice MRI can detect concealed CMBs.

Insight into specific pro-arrhythmic triggers in Brugada and early repolarization syndromes: results of long-term follow-up.

The pro-arrhythmic triggers in Brugada and early repolarization syndromes (BrS, ERS) have not been analyzed systematically except for case reports. We clinically investigated the circumstances which precede/predispose to arrhythmic events in these syndromes during long-term follow-up. A detailed history from the patients/witnesses was taken to investigate the antecedent events in the last few hours that preceded syncope/ventricular fibrillation (VF); medical records, ECG and blood test from the emergency room (ER) were reviewed. 19 patients that fulfilled the investigation criteria were followed up for 71 ± 49 months (34-190 months). Prior to the event (syncope/VF), the patients were partaking different activities in the following decreasing order; drinking alcoholic beverage, having meal, and getting up from sleep, exercise. 3 patients reported mental/physical stress prior to the event and 2 patients developed VF several days after starting oral steroid for treatment of bronchial asthma. In the ER, elevated J-wave amplitude (0.27 ± 0.15 mV) was found with 58 % of the patients having hypokalemia. After electrolyte correction and cessation of steroids, the following day plasma K+ (4.2 ± 0.3 mEq/L, P < 0.001) was significantly increased and J-wave amplitude (0.13 ± 0.1 mV, P < 0.001) was remarkably reduced. Three patients were kept on oral spironolactone/potassium supplements. During follow-up for 71 ± 49 (34-190) months, among 4 patients with VF recurrence, one patient developed VF after taking oral steroid. In ERS and BrS, hypokalemia and corticosteroid therapy add substantial pro-arrhythmic effects, but potentially treatable. Stopping steroid therapy and avoiding hypokalemia had excellent long-term outcome.

Late Gadolinium Enhancement on Cardiac MRI Correlates with QT Dynamicity Represented by QT/RR Relationship in Patients with Ventricular Arrhythmias.

BACKGROUND: The distribution of late gadolinium enhancement (LGE) on the cardiac MRI (CMR) indicates myocardial fibrosis and provides information of possible reentry substrates. QT dynamicity reflecting repolarization abnormalities has gained attention as a potential prognostic predictive factor. OBJECTIVE: To clarify the correlation between the LGE distribution on CMR and QT dynamicity represented by the QT/RR relationship. METHODS: CMR and QT/RR analyses using Holter monitoring were performed in 34 patients (24 males, 60 ± 11 years) with ventricular tachycardia (VT) and/or ventricular fibrillation (VF). The LGE on CMR was scored using a 4-point score in 17 left ventricular segments. The sum of the LGE scores was calculated for each patient. The QT/RR slope and daytime/nighttime QT/RR ratio (day/night ratio) were calculated. The correlation between the slope or the day/night QT/RR ratio and late enhancement findings was analyzed. RESULTS: All patients were divided into 23 LGE positive (LGE(+)) and 11 LGE negative (LGE(-)) patients. The slopes of the QTe/RR and QTa /RR were significantly steeper in the LGE(+) than in LGE(-) patients (0.21 ± 0.03 vs 0.13 ± 0.02; P < 0.001, 0.19 ± 0.03 vs 0.13 ± 0.02; P < 0.001, respectively), and both slopes were significantly correlated with the total LGE scores (r = 0.83, P < 0.001; r = 0.71, P < 0.001, respectively). In the LGE(+) patients, the QTe day/night (1.37 ± 0.38 vs 0.91 ± 0.33; P = 0.002) and QTa day/night ratios (1.33 ± 0.26 vs 1.06 ± 0.30; P = 0.011) were significantly greater than those in the LGE(-) patients. CONCLUSION: The LGE distribution was closely related to the QT dynamicity, suggesting that a combination of these markers can be a powerful tool for understanding the background pathophysiology.

Late gadolinium enhancement of cardiac magnetic resonance imaging indicates abnormalities of time-domain T-wave alternans in hypertrophic cardiomyopathy with ventricular tachycardia.

BACKGROUND: The presence of myocardial scar detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging has been described as a good independent predictor of mortality in patients with hypertrophic cardiomyopathy (HCM). Time-domain T-wave alternans (TWA) is also a potential predictor of cardiac mortality in patients with left ventricular dysfunction. OBJECTIVE: The purpose of this study was to elucidate the relationship between LGE distribution and TWA in patients with HCM. METHODS: CMR and TWA analyses using Holter monitoring were performed in 42 patients with HCM. The average transmural extent of LGE was scored as 1-4 in each segment, and the sum of the LGE scores (total LGE score) was calculated for each patient. The correlation between the maximal time-domain TWA voltage and LGE findings was analyzed, and the differences in time-domain TWA voltage, total LGE score, and cardiac function assessed by CMR imaging in the presence or absence of ventricular tachycardia (VT) were also compared. RESULTS: The total LGE score was significantly and positively correlated with the maximal time-domain TWA voltage (r = 0.59; P < .001). Furthermore, the total LGE score and maximal time-domain TWA voltage were significantly greater in patients who had episodes of VT (n = 21) than in those without VT (23 ± 7 vs. 10 ± 8; P < .001 and 87 ± 26 µV vs. 62 ± 12 µV; P < .001, respectively). However, the left ventricular ejection fraction did not statistically differ between patients with VT and those without VT (56% ± 14% vs. 61% ± 7%; P = .102). CONCLUSION: The magnitude of the localized LGE was significantly correlated with abnormalities in ventricular repolarization as assessed by TWA and QT dispersion.

Eosinophilic myocarditis without hypereosinophilia accompanied by giant cell infiltration.

A 53-year-old woman with a history of allergic disease was admitted to our hospital because of syncope induced by sustained ventricular tachycardia. The clinical course and the laboratory data did not correspond to those of acute myocarditis. Although eosinophils in the peripheral blood count were not increased, the diagnosis of eosinophilic myocarditis was made following a right ventricular endomyocardial biopsy that showed a remarkable infiltration of eosinophils. While giant cells were another histopathological feature of this case, they were considered to be an expression of the disease severity. This is a rare case of eosinophilic myocarditis, without peripheral eosinophilia. .

Repolarization characteristics in early repolarization and brugada syndromes: insight into an overlapping mechanism of lethal arrhythmias.

INTRODUCTION: We reported impaired QT-rate dependence in early repolarization syndrome (ERS); however, contemporary data have shown peak incidence of sudden cardiac death (SCD) in ERS and Brugada syndrome (BrS) at mid-night and early morning. Taken together, we analyzed the nocturnal QT-rate dependence in both syndromes. METHODS AND RESULTS: A total of 172 subjects were enrolled: 11 ERS, 11 BrS patients, 50 subjects with an uneventful ER pattern (ERP), and 100 non-J-wave control subjects. Ambulatory ECG-derived parameters (QT, QTc, and QT/RR slope) and day-night QT difference were analyzed and compared. Among the groups, there was no significant difference in the average QT or QTc; however, the 24-hour QT/RR slope was significantly smaller in ERS and BrS patients (0.103 ± 0.01 and 0.106 ± 0.01, respectively) than in the control group (0.156 ± 0.03, P < 0.001). Detailed analysis showed a lower day-night QT difference in ERS and BrS patients (19 ±18.7 and 24 ±14 milliseconds, respectively) than in the controls (40 ± 22 milliseconds, P = 0.007) with the lowest QT/RR slopes seen in the ERS and BrS groups from 0 to 3:00 am (QT/RR; 0.076 ± 0.02 vs. 0.092 ± 0.04 vs. 0.117 ± 0.04, for the ERS, BrS, and controls, respectively, P = 0.004) and from 3 to 6 am (QT/RR 0.074 ± 0.03 vs. 0.079 ± 0.02 vs. 0.118 ± 0.04, P < 0.001). CONCLUSION: In a large population of age- and gender-matched groups, both ERS and BrS patients showed attenuated QT-rate dependence and impaired QT day-night modulation that may provide a baseline reentrant substrate. Importantly, QT/RR maladaptation was most evident at mid-night and early morning, which may explain the propensity of such patients to develop SCD during this critical period.

Three cases of corticosteroid therapy triggering ventricular fibrillation in J-wave syndromes.

We describe three cases of J-wave syndrome in which ventricular fibrillation (VF) was probably induced by corticosteroid therapy. The patients involved were being treated with prednisolone for concomitant bronchial asthma. One of the three patients had only one episode of VF during her long follow-up period (14 years). Two patients had hypokalemia during their VF episodes. Corticosteroids have been shown to induce various types of arrhythmia and to modify cardiac potassium channels. We discuss the possible association between corticosteroid therapy and VF in J-wave syndrome based on the cases we have encountered.

Isolated cardiac sarcoidosis requiring open-chest myocardial biopsy for differentiation from malignant lymphoma.

A 68-year-old woman with a history of hypertension was admitted to our hospital because of dyspnea during physical exertion. Echocardiography demonstrated impaired left ventricular systolic function, and her ejection fraction was reduced to 30%. Coronary angiography did not show significant stenosis. Endomyocardial biopsy showed only nonspecific findings without noncaseating granulomas. Cardiac magnetic resonance (CMR) imaging showed transmural late gadolinium enhancement on the basal part of the left ventricle. 18F-Fluorodeoxyglucose positron emission tomography (18F-FDG PET) showed abnormal focal uptake specific to the left ventricle; no abnormal manifestations in other organs were observed. The CMR and 18F-FDG PET features could not rule out either sarcoidosis or malignant lymphoma. Therefore, we conducted open-chest myocardial biopsy to differentiate between the two possible diseases. Histopathological findings showed noncaseating epithelioid cell granuloma, confirming isolated cardiac sarcoidosis. This is an example of a challenging case of diagnosing isolated cardiac sarcoidosis. .

False tendon-related polymorphic ventricular tachycardia.

A 39-year-old woman showed nonsustained polymorphic ventricular tachycardia (PVT) during light physical activity. Cardiac multidetector row computed tomography demonstrated false tendons, one of which proved to be the focus triggering premature ventricular contraction (PVC) in electrophysiological studies. The triggered PVC arose during the diastolic period, which might have caused tension in the false tendon. Radiofrequency catheter ablation targeting the triggered PVC by pace mapping was performed and proved partially effective against PVT.