[CLINICAL EVALUATION OF EXTRASYSTOLIC ARRHYTHMIA AND CARDIAC FIBRILLATION].
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Both a long QTc and a large QTc dispersion (QTcd) can predispose infarcted patients to ventricular arrhythmias. The former simply reflects a general prolongation of ventricular recovery time, whereas QTcd is useful for revealing regional inhomogeneities of ventricular repolarization. The aim of our study was to evaluate QTc and QTcd behavior during exercise in 50 patients (all men) with previous myocardial infarction, and its possible correlation with the occurrence of exercise-induced premature ventricular complexes (EIPVC). Our patients underwent ergometric stress test with a load increase of 25 W, every 2 min, until the maximal age-related heart rate or symptoms were obtained, followed by a 10-min recovery phase. QTc and QTcd measurement was performed at rest (BS) and during exercise at two progressively increasing heart rate steps: 100-115 beats/min (T1) and 116-130 beats/ min (T2). The patients were divided into two groups according to the absence (group A; n = 22) or presence (group B; n = 28) of EIPVC. In terms of QTcd, no significant difference was found between the two groups at BS, T1, and T2. As for the mean QTc (QTcm), it was significantly longer in group B at BS (416 +/- 22 ms versus 395 +/- 19 ms; P = 0.001) and at T1 (431 +/- 24 ms versus 410 +/- 8 ms; P = 0.0001). When group B was further differentiated into two subgroups-Bx and Bz-according to the severity of EIPVC, we noted that patients with the most severe arrhythmic response (group Bz; n = 12) showed a persisting, significantly longer QTcm than group A (BS, 426 +/- 28 ms versus 395 +/- 19 ms; P < 0.05; T1, 445 +/- 24 ms versus 410 +/- 8 ms; P < 0.05; T2, 427 +/- 17 ms versus 412 +/- 14 ms; P < 0.05), and group Bx (n = 16) (BS, 426 +/- 28 ms versus 409 +/- 15 ms; P < 0.05; T1, 445 +/- 24 ms versus 420 +/- 19 ms; P < 0.05; T2, 427 +/- 17 ms versus 410 +/- 17 ms; P < 0.05). Group Bx showed a significantly longer QTcm than group A only at BS (409 +/- 15 ms versus 395 +/- 19 ms; P < 0.05). No significant difference in QTcd was found between the three groups at BS, T1, and T2. We also noted that the relationship between QTcm and QTcd was modified by the exercise, changing from a trend of direct relation at BS, towards an inverse one during effort, which reached significance at T2 (r = -0.319; P = 0.037). Based on our data, EIPVC occurrence seems to be more affected by the total duration rather than by regional inhomogeneities of the ventricular recovery time. In those patients with the most severe arrhythmic response, the autonomic modifications generated by the exercise succeed in attenuating only the regional inhomogeneities, but do not eliminate the differences in total duration of the repolarization period.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Ventricular ectopic activity is commonly encountered in clinical practice. Usually it is not associated with life-threatening consequences in the absence of significant structural heart disease. However, frequent ventricular ectopic beats can be highly symptomatic and even incapacitating in some patients. Currently, reassurance and pharmacological therapy are the mainstays of treatment. This study assesses the useful role of catheter ablation in eliminating drug refractory monomorphic ventricular ectopic beats in severely symptomatic patients. Eight patients were included, five patients had no heart disease and in three patients a structural heart disease was present (coronary artery disease in 1, hypertensive heart disease in 1, mitral valve prolaps in 1). The ejection fraction was higher than 40% in all patients (mean EF 56 +/- 14%). Mean number of ventricular ectopic activity was 29,295 +/- 10,650 VPB/24 h (1209 +/- 457 VPB/h) before ablation. No other spontaneous or induced arrhythmias were documented. The site of origin of ventricular ectopic activity was accurately mapped by using earliest endocardial activation time during ectopic activity or pace mapping, or both. The ectopic focus was located in the right ventricular outflow tract in five patients and in the left ventricle in three patients (posteroseptal 2, anterolateral 1). Frequent ventricular ectopic beats were successfully eliminated by catheter ablation in all patients. Early recurrence occurred in one patient after 10 min and 30 min after the procedure. In another patient a recurrence occurred 6 days after the procedure. In a second session he was successfully ablated and remained free of recurrence since 2 months. After ablation the mean number of ventricular premature beats was 211 +/- 159 VPB/24 h (9 +/- 7 VPB/h). The mean number of radiofrequency applications was 8 +/- 7 (range 2-22). Mean radiation time was 12 +/- 8 min. No complications were observed. During a mean follow-up of 6 months there were no further recurrences in the remaining six patients. Radiofrequency catheter ablation can be successfully used to eliminate monomorphic ventricular ectopic activity. It may therefore be a reasonable alternative for the treatment of severely symptomatic, drug resistant monomorphic ventricular ectopic activity.
The series of five patients with symptomatic isolated right ventricular outflow tract ectopy and no structural heart disease which were successfully treated with radiofrequency ablation of the ectopic focus are reported in order to discuss radio-frequency ablation as an alternative treatment in patients with right ventricular outflow tract ectopy without ventricular tachycardia.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.