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1/27. heart rate variability analysis of patients with idiopathic left ventricular outflow tract tachycardia: role of triggered activity.

    There have been several reports with respect to idiopathic ventricular tachycardias (VTs) originating from the left ventricular outflow tract (LVOT). A previous report suggested that triggered activity plays a partial role in idiopathic LVOT tachycardia from the electrophysiological as well as the electropharmacological viewpoint. However, the exact role of triggered activity in this type of VT remains unknown. In the present study the relationship of the frequency of premature ventricular contractions (PVCs) and heart rate was examined and heart rate variability (HRV) was analyzed in 2 cases of LVOT tachycardia using 24-h Holter electrocardiographic (ECG) monitoring. The relation between the PVCs frequency and heart rate showed a persistently positive correlation, indicating frequent PVCs as heart rate increased. In HRV analysis, NN50(%), a time-domain variable of parasympathetic activity, showed no change prior to ventricular arrhythmias. In frequency-domain analysis of HRV, the high frequency (HF) component tended to fall prior to repetitive PVCs and VTs. The ratio of the low frequency to high frequency (LF/HF) components increased prior to single PVCs, repetitive PVCs and VTs. Sympathetic predominance predisposes the genesis of these kinds of arrhythmias originating from the LVOT and it is suggested that triggered activity plays an important role in LVOT tachycardia, at least in its initiation.
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2/27. First evidence of premature ventricular complex-induced cardiomyopathy: a potentially reversible cause of heart failure.

    tachycardia-induced cardiomyopathy is a well-recognized and reversible condition, but left ventricular dysfunction due to frequent isolated premature ventricular complexes (PVCs) has not been reported. We observed resolution of dilated cardiomyopathy in a patient after a focal source of PVCs was eliminated by radiofrequency ablation. In a subset of patients with heart failure, PVC-induced cardiomyopathy may be a potentially reversible cause of left ventricular dysfunction.
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3/27. Radiofrequency catheter ablation from the left sinus of valsalva in a patient with idiopathic ventricular tachycardia.

    We report the case of a 54-year-old woman with idiopathic VT originating in the left ventricular outflow tract. She initially presented with palpitations and light-headedness. The morphology of the PVCs exhibited an inferior axis and tall R waves were noted in all the precordial leads. Spontaneous PVCs were transiently terminated by an intravenous injection of adenosine triphosphate. Radiofrequency catheter ablation from the left sinus of valsalva successfully abolished the PVCs and the VT.
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keywords = wave, frequency
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4/27. Effect of three emergency pacing modalities on cardiac output in cardiac arrest due to ventricular asystole.

    Pacing is a well recognised treatment in asystolic arrest with residual p wave activity. This can be achieved by transvenous, transthoracic, or manual external (cardiac percussion) pacing techniques. We report a case of ventricular asystole in which all three pacing modalities were applied, and demonstrate their relative effectiveness with invasive haemodynamic monitoring data. stroke volumes were comparable with all three methods. Manual external pacing is an effective holding measure when cardiac output is compromised due to bradycardia or asystole with residual p wave activity before more definitive pacing techniques are instituted.
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5/27. Class I antiarrhythmic drug and coronary vasospasm-induced T wave alternans and ventricular tachyarrhythmia in a patient with brugada syndrome and vasospastic angina.

    A 50-year-old man presented with a history of transient chest pain and palpitations. The 12-lead ECG at rest showed normal sinus rhythm. A slight ST segment elevation was observed in leads V1 to V3. During hospitalization, atrial fibrillation developed, and oral pilsicainide was administered. Thirty minutes after the drug was given, the ECG showed marked ST segment elevation in leads V1 to V3, and T wave alternans became visible in leads V2 and V3. Self-terminating ventricular tachycardia was initiated following frequent ventricular premature complexes, which showed a left bundle branch block pattern. The coronary angiogram was normal, but in the provocation test of vasospastic angina, acetylcholine administration into the left coronary artery resulted in complete occlusion of the left anterior descending and circumflex arteries. Marked ST segment elevation developed in leads I, aVL, and V3 to V6 concomitant with visible QT/T alternans in leads V4 and V5, and ventricular tachyarrhythmia was initiated. brugada syndrome and vasospastic angina coexisted in this patient, and T wave alternans can be used as a predictor of ventricular tachyarrhythmias in such patients.
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6/27. Spontaneous T wave alternans and premature ventricular contractions during febrile illness in a patient with brugada syndrome.

    A 69-year-old man who had experienced syncope and ventricular fibrillation was referred to our hospital. ECG showed a right bundle branch block pattern with ST segment elevation in the right precordial leads. When the patient presented to the hospital with febrile illness, spontaneous T wave alternans and premature ventricular contractions were observed. When the patient became afebrile, ST segment elevation improved, and T wave alternans and premature ventricular contractions disappeared.
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7/27. A case of cardiomyopathy induced by premature ventricular complexes.

    tachycardia-induced cardiomyopathy is a well-known and reversible condition, but the left ventricular dysfunction caused by frequent isolated premature ventricular complexes (PVCs) has been rarely reported. Apparent dilated cardiomyopathy was resolved in a patient after the focal source of PVCs was eliminated by radiofrequency catheter ablation. echocardiography showed progressive improvement of the abnormal wall motion. Frequent PVCs could be the cause of left ventricular dysfunction in a subset of patients with dilated cardiomyopathy and radiofrequency ablation should be the choice of therapy in those patients.
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8/27. ventricular fibrillation: ablation of a trigger?

    We report the case of a patient with recurrent ventricular fibrillation (VF) and no evidence of structural heart disease. VF was consistently initiated by a relatively early-coupled premature ventricular contraction with identical morphology on each occasion. Treatment with antiarrhythmic agents failed to suppress the arrhythmia. Electrophysiologic testing showed high-frequency potential at the earliest activation site, and radiofrequency ablation resulted in abolition of the ventricular ectopy with no further VF recurrence. Suppression of VF arising from focal triggers in patients with frequent ventricular ectopy and normal heart can be achieved with catheter ablation, but further studies are needed to evaluate the prevalence of such a mechanism.
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9/27. Idiopathic monomorphic ventricular tachycardia originating from the left aortic sinus cusp in children: endocardial mapping and radiofrequency catheter ablation.

    BACKGROUND: Idiopathic repetitive monomorphic ventricular tachycardia with an inferior axis and left bundle branch block pattern typically originates from the superior right ventricular outflow tract. When indicated, radiofrequency catheter ablation is usually safe and effective. However, a left ventricular origin has been described recently in adult patients in whom ablation attempts in the right ventricular outflow tract were unsuccessful. Experience in pediatric patients is limited. patients AND methods: Since 1998, 13 young patients suffering from symptomatic ventricular tachycardia episodes with an inferior axis and left bundle branch block pattern underwent an electrophysiological study and radiofrequency catheter ablation. In 2 patients, age 13 and 15 years, no endocardial local electrograms preceding the surface ECG QRS complex could be recorded within the right ventricular outflow tract during ventricular ectopy. Detailed mapping within the left ventricular outflow tract and in the aortic root revealed local electrograms 25 and 53 ms earlier than the QRS complex and a 11/12 and 12/12 lead match during pacing inferior and anterior to the ostium of the left main coronary artery in the left aortic sinus cusp. Earliest activation was recorded 10 and 12 mm away from the coronary artery ostium identified angiographically. In each of the patients, one single radiofrequency current application (60 degrees C, 30 W, duration 30 and 60 s, respectively) resulted in complete cessation of ventricular ectopy. Subsequent selective injection into the left coronary artery did not reveal any abnormalities. During follow-up (2 and 34 months) off any antiarrhythmic drugs, both of the patients are in continuous normal sinus rhythm. CONCLUSION: In young patients with symptomatic idiopathic ventricular tachycardia originating from the left aortic sinus cusp, radiofrequency catheter ablation was safe and effective.
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keywords = frequency
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10/27. A case of a short-coupled variant of torsades de pointes with electrical storm.

    This case report describes a short-coupled variant of torsades de pointes with a characteristic ECG pattern consisting of a prominent J wave in leads V3-V6, in which an electrical storm was evoked with autonomic receptor stimulation and a blockade test. The patient's frequent VF attacks were triggered by short-coupled premature ventricular contractions with a right bundle branch block morphology and left-axis deviation, and were suppressed by deep sedation followed by a combination therapy using verapamil and mexiletine. Interestingly, with the use of those drugs, the prominent J wave diminished. The mechanism underlying this syndrome is discussed.
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ranking = 16.94361626778
keywords = wave
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