Sotalol-induced coronary spasm in a patient with dilated cardiomyopathy associated with sustained ventricular tachycardia

A 54-year-old man with severe left ventricular dysfunction due to dilated cardiomyopathy was referred to our hospital for symptomatic incessant sustained ventricular tachycardia (VT). After the administration of nifekalant hydrochloride, sustained VT was terminated. An alternate class III agent, sotalol, was also effective for the prevention of VT. However, one month after switching over nifekalant to sotalol, a short duration of ST elevation was documented in ECG monitoring at almost the same time for three consecutive days. ST elevation with chest discomfort disappeared since he began taking long-acting diltiazem. Coronary vasospasm may be induced by the non-selective beta-blocking properties of sotalol.     

Elevated troponin levels after prolonged supraventricular tachycardia in patient with normal coronary angiography

The European Society of Cardiology and the American College of Cardiology redefined the concept of myocardial infarction in the presence of highly positive markers of myocardial injury associated with at least one of the following: ischemic symptoms; development of pathologic Q waves on the ECG or ECG changes indicative of ischemia (positive or negative deviation of the ST segment), making troponins one of the most important aspects in the evaluation and stratification of patients with chest pain in the emergency room. However, although troponin gives excellent accuracy in the identification of myocardial necrosis, it is known that it can also be elevated in a series of nonatherosclerotic heart diseases. We present the case of a 49-year-old female patient admitted to the Chest Pain Unit with a history of supraventricular tachycardia associated with chest discomfort, nausea and diaphoresis. During risk stratification, the patient presented with a high serum troponin T level (0.143 ng/ml) but with a normal coronary angiography.     

Positive cardiac troponin I and T and chest pain in a patient with iatrogenic hypothyroidism and no coronary artery disease

We report about a 41-year old male patient who presented to the emergency room with acute chest pain, exertion dyspnoea, muscle stiffness, myalgia and adynamia. There was no history of coronary artery disease but known arterial hypertension and insulin dependent diabetes mellitus. Four weeks before submission the patient had been thyroidectomized after he had been diagnosed with papillary thyroid carcinoma and was now awaiting further radioiodine therapy. The thyroid-stimulating hormone level was markedly elevated to 67 mU/l (normal range 0.27-4.20 mU/l) and fT4 significantly reduced to 0.19 ng/ml (normal range 0.9-1.9 ng/ml). CK was elevated to 328 U/l, cardiac Troponin I (Stratus CS) above the threshold with 0.13 microg/l and Elecsys third generation troponin T above the threshold with 0.04 microg/l. The electrocardiogram showed a normal sinus rhythm and did not reveal any signs of ST-elevation or -depression. During follow-up a cardiac MRI was performed, showing normal dimensions and function but a very small area of diffuse myocardial damage, atypical of ischemic injury. In coronary angiography normal coronary arteries were found. We conclude that cardiac troponins I and T may be elevated in severe hypothyroidism without coronary artery disease due to diffuse myocardial injury which can be imaged by MRI.     

Procainamide induced sustained monomorphic ventricular tachycardia in a patient with benign premature ventricular complexes

A 59-year old female with history of benign ventricular ectopy who developed sustained monomorphic ventricular tachycardia (VT) during therapy with procainamide is reported. The tachycardia occurred 24 hours after institution of procainamide without any other evidence of drug toxicity or QT prolongation. When procainamide was withheld, VT resolved completely and no arrhythmia could be induced by programmed ventricular stimulation. When the patient was rechallenged with procainamide at therapeutic level, sustained monomorphic VT was initiated reproducibly by programmed ventricular stimulation. Without antiarrhythmic therapy, patient has been asymptomatic and free of recurrent VT after a follow-up of 9 months. This case: Demonstrates that procainamide may cause the first emergence of sustained monomorphic VT in a patient with no previous history of VT; and Emphasizes the utility of programmed ventricular stimulation in providing direct evidence for drug mediated exacerbation of the ventricular arrhythmia.     

Predictors of sustained ventricular tachycardia inducibility in patients with nonsustained ventricular tachycardia and chronic coronary artery disease

To assess the likelihood of inducing sustained ventricular tachycardia, we analyzed a cohort of 58 retrospective and 18 prospective patients with chronic coronary artery disease who underwent electrophysiologic study because of spontaneous nonsustained ventricular tachycardia (three or more beats, lasting less than 30 seconds, at a rate greater than 100/min). In 24 of the 58 retrospective patients (41%) sustained ventricular tachycardia was inducible. Stepwise logistic regression identified two "major" variables--left ventricular aneurysm/dyskinesis/akinesis (p = 0.0001; relative risk = 11.88) and ejection fraction less than 40% (p = 0.0002; relative risk = 9.69)--and one "minor" variable--nonsustained ventricular tachycardia longer than 10 beats (p = 0.0151; relative risk = 4.21)--as significant predictors of inducibility. Nineteen patients with both major variables had a high probability of inducibility (greater than 90%). Nineteen patients with neither major variable had a low probability of inducibility (less than 5%). The remaining 20 patients with only one of the major variables had an intermediate probability of inducibility (14% to 75%). The significance of the third minor factor, nonsustained ventricular tachycardia longer than 10 beats, was confined to this intermediate group, in which it could be used to segregate relatively high (65% to 75%) and relatively low (14% to 20%) probability of inducibility. Prospective application of the predictor function stratified 18 additional patients into three groups with high (six patients), intermediate (seven patients), and low (five patients) probability of inducibility. The observed rate of inducibility in each group was 5 of 6 (83%), 2 of 7 (29%), and 0 of 5 (0%), respectively. These data suggest that patients with nonsustained ventricular tachycardia and chronic coronary artery disease can be stratified into subgroups with high, intermediate, and low probability of inducibility of sustained ventricular tachycardia on the basis of ejection fraction and regional ventricular wall motion defects alone.     

冠心病持续性室性心动过速患者的Q—T离散度

为评价Q-T_d对冠心病患者发生室性心动过速的预测价值,观察18例冠心病持续性室性心动过速患者和20例对照组的Q-T_d。结果显示持续型室性心动过速组Q_(Td)(104±28ms)明显大于对照组(61±19ms,P<0.01)。表明Q-T_d的增加可作为预测室性心动过速发生的重要指标。     

Automatic, implantible cardioverter-defibrillator in a patient with chronic Chagas cardiopathy and sustained ventricular tachycardia]

We studied a 48 years old woman, with chronic Chagasic cardiopathy, manifested with cardiomegaly, heart failure and syncope, due to a sustained ventricular tachycardia (SVT) of two different configurations (left bundle branch block and right bundle branch block). During electrophysiological testing, both types of ventricular tachycardia were reproduced. Successful ablation therapy of the right branch of His was performed due to suspicion of the bundle branch reentrant tachycardia, with a left bundle branch block. The patient continued to show SVT episodes, now with right bundle branch block pattern. Cardioverter Defibrillator was implanted. We report this case due to the rare frequency of Chagas' disease, where it could be a cause of heart disease, since the existence of the parasite (trypanosoma cruzi) and its vector (Triatoma) has been identified in some rural and suburban zones in the state of Aguascalientes, Mexico.     

Recurrent sustained ventricular tachycardia solely responsive to verapamil in a patient with a remote myocardial infarction

A 49-year-old man with a silent remote postero-inferior wall myocardial infarction exhibited recurrent episodes of sustained ventricular tachycardia which was hemodynamically well tolerated. Ventricular tachycardia was neither terminated nor prevented by therapy with multiple class I and class III antiarrhythmic drugs. In contrast, ventricular tachycardia was repeatedly terminated within a few minutes following intravenous administration of 10 mg verapamil and did not recur during oral therapy with verapamil (360 mg daily). Electrophysiologic study suggested that ventricular tachycardia was due to a reentrant mechanism rather than to triggered or abnormal automaticity. Thus, in contrast to previous reports, findings in this patient indicate that verapamil may be very effective and safe in certain types of ventricular tachycardia occurring late after a myocardial infarction.     

冠状动脉造影正常的左心室室壁瘤1例

目的报道罕见特殊左心室室壁瘤1例。方法根据冠状动脉造影及超声心动图结果综合判定。结果超声心动图示心尖部局部变薄,膨出,收缩活动消失。冠状动脉造影未能显示有明确的冠状动脉狭窄病变。结论患者冠状动脉造影正常结果考虑左冠状动脉前降支持久痉挛及/或不稳定斑块所致,后者可诱发血栓形成,随血栓溶解,血管再通。     

Transition from purkinje fiber-related rapid polymorphic ventricular tachycardia to sustained monomorphic ventricular tachycardia in a patient with a structurally normal heart: a case report

We describe a 17-year-old woman with a structurally normal heart in which short-sustained rapid polymorphic ventricular tachycardias (VTs) were repetitively provoked by an antiarrhythmic agent, pilsicainide, and spontaneously changed into a sustained monomorphic VT. The latter was terminated by verapamil and was shown to be due to reentry by entrainment. Those two VTs originated from the Purkinje fibers in the left ventricular septum. Radiofrequency catheter ablation guided by the diastolic double potentials eliminated both VTs. Neither tachycardia recurred over a 5-month follow-up period or during antiarrhythmic drug challenge tests at 1 week, 1 month, and 3 months after the ablation.     

Transmural ventricular activation during consecutive cycles of sustained ventricular tachycardia associated with coronary artery disease

Although computerized mapping has enabled the intraoperative delineation of global ventricular activation from a single complex of ventricular tachycardia (VT), beat-to-beat reproducibility of isochronic maps has not been defined. To determine the reliability of single-beat analysis, epicardial and transmural ventricular electrograms during 6 consecutive VT cycles were analyzed in 10 patients during intraoperative mapping of sustained monomorphic VT. Bipolar electrograms were recorded simultaneously using sock and needle electrodes from up to 96 epicardial and 156 transmural sites. In each patient, at each electrode site, local activation time, electrogram duration and morphology were compared over 6 consecutive beats. A total of 9,816 electrograms were analyzed. For each patient, the isochronic activation map during VT was reproducible. Mean beat-to-beat variations in local epicardial and transmural activation times were only 1.7 +/- 1.7 and 2.04 +/- 1.9 ms, respectively (difference not significant). Moreover, electrogram duration did not vary significantly. Mean variations in epicardial and transmural electrogram durations were 2.1 +/- 1.8 and 1.4 +/- 1.9 ms, respectively (difference not significant). There were only 2 instances of 2:1 conduction failure; both occurred intramurally and adjacent to a site of VT origin. Thus, transmural ventricular activation during sustained monomorphic VT is reproducible regardless of electrode site or electrogram duration. These results demonstrate that analysis of a single beat of VT is a reliable and expedient method to delineate ventricular activation during intraoperative computerized mapping for the purpose of clinical decision-making in patients with sustained monomorphic VT.     

Idiopathic recurrent sustained parasystolic ventricular tachycardia responsive to verapamil in a 15-year-old patient

A 15-year-old patient is presented with parasystolic ventricular tachycardia which was responsive to oral verapamil. We emphasize the value of verapamil in the treatment of this uncommon arrhythmia.     

Mid-ventricular obstructive hypertrophic cardiomyopathy associated with an apical aneurysm and sustained ventricular tachycardia: a case report]

A 60-year-old woman presented with mid-ventricular obstructive hypertrophic cardiomyopathy associated with an apical aneurysm and sustained ventricular tachycardia. She was admitted because of drug refractory ventricular tachycardia. She had been treated with several antiarrhythmic agents, including amiodarone, but symptomatic episodes had continued. Echocardiography, magnetic resonance imaging, and left ventriculography showed mid-ventricular obstructive hypertrophic cardiomyopathy with an apical aneurysm. Electrophysiological study easily reproduced sustained pleomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and ventricular fibrillation. The patient underwent implantation of a cardioverter-defibrillator. The relationship between mid-ventricular hypertrophic cardiomyopathy and apical aneurysm is unknown, but mid-ventricular hypertrophic cardiomyopathy is one of the causes of severe ventricular arrhythmias and sudden death.     

Periodicity of global ventricular activation of sinus beats in patients with coronary artery disease and sustained ventricular tachycardia

Despite increasing clinical reliance on signal-averaged electrocardiograms for determining risk for development of sustained ventricular tachycardia (VT), the periodicity of global ventricular activation during sinus rhythm has not been defined. Accordingly, epicardial and transmural ventricular electrograms during 6 consecutive sinus beats were evaluated in 10 patients with abnormal signal-averaged electrocardiograms who were undergoing surgery for VT. Bipolar electrograms were recorded with sock and needle electrodes from up to 96 epicardial and 156 transmural sites. Electrogram morphology, duration and activation were compared on a beat-to-beat basis. In all, 9,816 electrograms were analyzed. Mean durations of epicardial and transmural electrograms were 33 +/- 16 ms (range 6 to 199) and 23 +/- 10 ms (range 6 to 72), respectively, with a beat-to-beat variation of 1.9 +/- 1.4 ms per site. Similarly, local activation times did not vary significantly during the 6 cardiac cycles analyzed (mean variation 1.7 +/- 2.0 ms). Local conduction failure was not observed. Although electrograms during the terminal 40 ms of the QRS were significantly longer (36 +/- 20 vs 26 +/- 12 ms, p less than 0.001) when compared with those recorded earlier during the QRS complex, beat-to-beat variation in duration (2.1 +/- 1.6 ms) and activation (1.7 +/- 2.3 ms) was not significant. Results demonstrate that epicardial and transmural electrograms recorded during sinus rhythm in patients with sustained VT are periodic signals and thus establish a physiologic basis for signal averaging of electrocardiographic waveforms in these patients.     

Naxos disease presenting with ventricular tachycardia and troponin elevation

Naxos disease is a recessively inherited stereotype association of arrhythmogenic cardiomyopathy with a cutaneous phenotype, characterized by peculiar woolly hair and palmoplantar keratoderma. The cardiomyopathy clinically manifests by adolescence and the symptomatic presentation is usually with syncope and/or sustained ventricular tachycardia of left bundle branch block configuration. We report the case of a 43-year-old man without any history of heart disease who was admitted to the hospital because of an episode of sustained ventricular tachycardia and troponin I elevation, in the absence of coronary artery disease. Diagnostic workup, including genetic assessment, revealed Naxos disease as the underlying cause. In this case, acute myocarditis seems to be the most plausible explanation for the nonischemic myocardial injury.