ABSTRACT
PURPOSE: To evaluate some features of ventricular arrhythmias in patients with mitral valve prolapse. METHODS: We studied 25 patients (female: 19; mean age: 37 +/- 13 years) with ventricular arrhythmias, mitral valve prolapse and normal ventricular function. All patients underwent a 24h Holter and high resolution ECG (HRECG). The Qtc intervals were measured in lead II (normal < 0.44 s). In order to define the possible origin of the ventricular focus, the morphology of the ectopic beats were analysed in leads I, II, aVF, V1 using the following criteria: 1) LBBB morphology with left axis deviation in the frontal plane (FP): origin at the inflow tract of the right ventricle (RV); 2) LBBB morphology with right axis deviation in the FP: origin at the outflow tract of the RV; 3) RBBB morphology with left axis deviation in the FP: origin at the posterior region of the left ventricle (LV). RBBB morphology with right axis deviation in the FP: origin at the anterior region of the LV. RESULTS: Twenty three (92) patients showed > 720 isolated ventricular ectopic beats/24 h. Paired ventricular response was detected in 18 (72) patients and non-sustained VT in 15 (60). HRECG was positive in six (24) patients and Qtc interval was prolonged in 13 (52). RV was the site of origin of the ventricular ectopic beats in 85 of the patients (outflow: 85; inflow: 15). Only five (20) patients had arrhythmias from the LV. CONCLUSION: There was a high incidence of ventricular arrhythmias with a low incidence of positive HRECG tests, suggesting that the mechanisms of the arrhythmias do not correlate with slow intramyocardial conduction. It was noted a strong association between mitral valve prolapse, arrhythmogenic right ventricular disease and Qtc prolongation. It is possible that in some of this patients the finding could represent a global myocardial disease.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Arrhythmias, Cardiac , Mitral Valve Prolapse , Ventricular Dysfunction, Right/complications , Arrhythmias, Cardiac , Prospective Studies , Mitral Valve Prolapse , Electrocardiography , Electrophysiology , Analysis of Variance , Ventricular Dysfunction, RightABSTRACT
A presente investigaçäo teve por objetivo avaliar os efeitos do Sotalol sobre o eletrocadiograma de alta resoluçäo (ECGAR), em uma populaçäo com arritmia ventricular idiopática. Foi estudado um grupo de 12 pacientes submetidos a um ensaio clínico do tipo duplo-cego cruzado e randomizado, para avaliaçäo da eficácia da droga. Foram obtidos ECGAR em condiçöes de controle (C), uso de placebo (P) e de droga (D). confrontando os resultados entre as três situaçöes e a eficácia medicamentosa. No vetor-magnitude foram analisados os seguintes parâmetros: voltagem média dos 40ms terminais do complexo QRS filtrado (VM - normal > 20 µV), duraçäo dos sinais de baixa amplitude < 40 µV no final da ativaçäo (SBA - normal < 38ms) e duraçäo total do complexo QRS filtrado (DQRS - normal < 114.0ms). Em funçäo da resposta terapêutica, os pacientes foram divididos em responsivos (G1) e näo-responsivos (G2). Näo foram observadas diferenças estatisticamente significativas entre C e P. No grupo I, composto por 5 pacientes (42 'por cento' de eficácia), näo foram observadas diferenças significativas nas 3 variáveis avaliadas entre as condiçöes de P e D. No grupo II, composto por 7 pacientes, ocorreram modificaçöes nos SBA, cujos valores no P estavam em 24.80 ñ 7.60ms e passando com D para 29.10 ñ 14.76ms (p<0,01). Em 5 dos 7 pacientes deste grupo (71 'por cento'), prolongam-se no pós-droga os SBA, numa média de 11.20 ñ 4.80ms, com significância estatística em relaçäo ao placebo (p<0,04). Frente aos resultados observados com os SBA, foram obtidos sensibilidade de 71'por cento', especificidade de 86 'por cento', valor preditivo positivo de 83 'por cento' e negativo de 75 'por cento' para definir a populaçäo responsiva à droga. Concluiu-se que na populaçäo estudada, o Sotalol, quando efetivo, nço produziu modificaçöes significativas nos parâmetros do ECGAR. Um incremento médio dos SBA de 11.2 ñ 4.8ms, por influência da droga, associou-se a uma ausência de resposta terapêutica.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Electrocardiography , Electrocardiography/instrumentation , Sotalol/therapeutic useABSTRACT
PURPOSE--To use a new approach in order to assess the antiarrhythmic drugs, based in the hourly autonomic effects and antiarrhythmic efficacy of sotalol. METHODS--Sixteen patients were evaluated in a randomized double-blind placebo-controlled study. Patients were classified in group 1 (anti-arrhythmic efficacy) and group 2 (no antiarrhythmic efficacy). The following parameters were analyzed: 1) clinical variables as age, gender, cardiac disease and ventricular ectopies density; 2) drug effects on pNN50 in 24-hour and on mean hourly cardiac cycle length; 3) percentage of hourly ventricular ectopies distribution and its correlation with pNN50 and with mean hourly cardiac cycle length in all patients; 4) drug effects on mean hourly cardiac cycle length in groups 1 and 2; 5) correlation between hourly pNN50 and ventricular ectopies density after sotalol administration in groups 1 and 2; 6) hourly drug efficacy in groups 1 and 2 and correlation with pNN50. RESULTS--Efficacy of the drug was present in 8 (50) patients. Sotalol significantly increased 24-hour pNN50 (placebo 5.01 +/- 2.02; after drug, 11.70 +/- 5.59-p < 0.001), also increasing mean hourly cardiac cycle length during the day and night, in all patients (placebo 758.25 +/- 75.68 ms; after drug 967.71 +/- 80.17 ms-p < 0.000). It was noted that patients under placebo had different autonomic tonus; group 1 showed higher sympathetic activity as compared to group 2. Hourly drug efficacy was seen in 23 of 24-hour recordings in group 1 while it was not seen at any time in group 2. CONCLUSION--Sotalol significantly increased parasympathetic cardiac activity. The anti-arrhythmic response was related to the autonomic tonus seen before and after drug administration.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Arrhythmias, Cardiac , Sotalol , Anti-Arrhythmia Agents/therapeutic use , Sotalol , Electrocardiography, Ambulatory , Circadian Rhythm , Anti-Arrhythmia Agents/pharmacology , Double-Blind Method , Autonomic Nervous System/physiologyABSTRACT
PURPOSE--To evaluate the effects of sotalol in patients (pts) with idiophatic ventricular arrhythmias (VT) from right ventricular outflow tract. METHODS--Eighteen pts with VT were enrolled (five with monomorphic repetitive ventricular tachycardia - MRVT). Pts were submitted to a double-blind crossover randomized study (placebo vs. 320 mg/po/d/sotalol; four weeks each), after a wash-out control period. Holter recording were recorded in control and placebo and drug periods. Eligible pts have > 50/h isolated ventricular premature beats (VPB) in control, with or without paired VPB or nonsustained VT (NSVT- > 3 beats, > 100bpm). Drug efficacy criteria was: > 75//reduction in isolated VPB and > 90//of paired VPB or NSVT. The effects of the drug on uncorrected QT interval was evaluated and also on circadian rhythm of VT through the hourly pNN50/VPB ratios. Values are given as mean +/- SD. Three recordings were compared by using paired Student's ®t® test. Statistical significance was assumed for p < 0.05. RESULTS--Differences between control and placebo were NS. Drug was effective in 61//of pts, reducing the 3 types of ET (VPB: placebo = 23.508 +/- 34.537; drug: 975 +/- 1357; paired placebo = 443 +/- 587; drug = 9 +/- 20). The drug was evaluated in 4 pts with MRVT, reducing all ectopic events, with efficacy of 60//over VPB and paired and 80//over NSVT (VPB: placebo = 52.639 +/- 42.207; drug: 1631 +/- 2062; paired: placebo = 796 +/- 754; drug: 20 +/- 30; NSVT: placebo = 4287 +/- 6343; drug: 9 +/- 11). Mean QT interval was 0.40 +/- 0.01s in control and 0.50 +/- 0.04s in the drug period, with no correlation between duration and efficacy. Sotalol modified the circardian rhythm of VPB in the non-responders group, mainly during the morning. CONCLUSION--Sotalol was effective in control of VT, mainly the MRVT. Its effect on VPB circadian rhythm may independently contribute to the overall efficacy profile and myocardial protective effect of this drug
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Sotalol/therapeutic use , Tachycardia, Ventricular/drug therapy , Circadian Rhythm/drug effects , Double-Blind MethodABSTRACT
PURPOSE--To evaluate by the signal averaged-ECG (SAECG) the initial portion of the activation of the sustained ventricular tachycardia (SVT) and monomorphic repetitive ventricular tachycardia (MRVT), correlating the findings with those obtained during sinus rhythm (SR). METHODS--Ten patients was studied; five with SVT and five with MRVT. Patients with SVT presented a positive SAECG while patients with MRVT the test was negative, during SR. The findings of this two populations were compared with those obtained in a group of ten patients with advanced bundle branch block (ABBB--five RBBB and five LBBB). We analyzed in the vector-magnitude obtained during VT and ABBB, the root mean square of the initial 40 ms portion of the activation (RMS40) and the duration of the low amplitude signals < 40 microV from the beginning of the filtered QRS (LAS). To define the positiveness of the test in SR, we analyzed the final RMS40 (normal > 20 microV), the duration of the LAS < 40 microV at the end of the activation (normal < 38 ms) and the total QRS duration (QRSD-normal < 114 ms). RESULTS--(mean)-SVT in SR: RMS40 = 11.2 +/- 6.2 microV; LAS = 47.4 +/- 5.8 ms; QRSD = 131.2 +/- 8.7 ms. SVT during VT: RMS40 = 6.9 +/- 4.5 microV; LAS = 54.5 +/- 9.1 ms. RMVT in SR: RMS40 = 59.7 +/- 49.0 microV; LAS = 28.3 +/- 8.5 ms; QRSD = 93.1 +/- 13.0 ms. MRVT during VT: RMS = 25.2 +/- 8.8 microV; LAS = 28.9 +/- 11.1 ms. RBBB: RMS = 53.3 +/- 34.2 microV; LAS = 22.6 +/- 9.8 ms. LBBB: RMS = 54.7 +/- 37.3 microV; LAS = 11.4 +/- 4.6 ms. The comparison between the data from SVT and MRVT/ABBB showed p < 0.01. CONCLUSION--In the studied population, the SAECG was able to identify abnormal LAS initiating SVT, that were not present in MRVT and ABBB. This signals probably represents intra-myocardial slow conduction, as a portion of a re-entry circuit. There was an excellent correlation between the findings during SVT and MRVT with those obtained in SR
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Tachycardia, Ventricular/diagnosis , Electrocardiography , Tachycardia, Ventricular/physiopathology , Action Potentials/physiologyABSTRACT
PURPOSE--To evaluate retrospectively clinical features of repetitive monomorphic ventricular tachycardia (RMVT). METHODS--Files of 11 patients with RMVT were analyzed (9 females, mean-age 37 +/- 17 years). All patients were submitted to clinical evaluation, ECG, Holter monitoring stress test, high-resolution ECG and echocardiogram; they were treated with antiarrhythmic drugs. RESULTS--Patients were in NYHA class I or II, 9 asymptomatics and 2 with palpitations. The ECG was normal in all of them. Cardiac memory was observed in 3. A left bundle branch block with inferior axis deviation in the frontal plane was present during RMVT in all patients (right ventricular outflow tract focus). Holter monitoring revealed mean of 12031 +/- 8345 isolated PVC/24h; 2892 +/- 234 ventricular couplets/24h and 1367 +/- 890 VTs/24h (mainly nonsustained). In 6 patients RMVT was suppressed during maximal exercise treadmill. High-resolution ECG was negative in all group. Five patients had a normal echocardiogram while 5 showed mitral valve prolapse. One patient developed tachycardiomyopathy. The arrhythmia was controlled with 320mg of oral sotalol in 3 of 4 that used this drug and with 120mg oral propranolol in one of 6 that used this drug. Drug resistance was present in the others. The mean follow-up period was 38 +/- 16 months. CONCLUSION--The results demonstrate that RMVT is a benign form of VT with no detectable anatomic substract by the currently used methods. It is probably induced by nonreentrant mechanism and frequently drug resistance is observed. Among the antiarrhythmic drugs commonly used, sotalol showed to be the most effective
Objetivo - Avaliar, retrospectivamente, os dados clínicos mais relevantes da taquiarritmia ventricular monomórfica repetitiva (TVMR). Métodos - Foram analisados os registros de 11 pacientes, 9 femininos, idade média de 37±17 anos, portadores de TVMR, todos submetidos à avaliação clínica seqüencial, ECG, Holter, prova de esforço em esteira, ECG de alta resolução (ECGAR) e ecocardiograma, sendo tratados com drogas antiarrítmicas. Resultados - Os pacientes encontravam-se em classe funcional I/II da NYHA, sendo 9 assintomáticos e 2 com queixas de palpitações. O ECG, em ritmo sinusal, foi normal nos 11 pacientes, havendo em 3 o fenômeno de memória cardíaca. O ECG durante a taquicardia mostrou QRS com BRE e eixo inferior no plano frontal (foco em via de saída de VD) em todo o grupo. O Holter mostrou no total dos pacientes, média de 12031±8345 extra-sístoles nas 24h; pareadas de 2892±234 e surtos de TV de 1367±890, a maioria não-sustentados. A prova de esforço aboliu a taquiarritmia no esforço máximo em 6 pacientes. O ECGAR foi negativo em todo o grupo. Cinco pacientes apresentavam ecocardiogramas normais, havendo em 5, sinais de prolapso da válvula mitral. Um paciente evoluiu com sinais de taquicardiomiopatia. A arritmia foi controlada em 3 pacientes com 320mg de sotalol VO (4 fizeram uso desta droga) e em 1 com 120mg de propranolol VO (usado em 6 pacientes), havendo nos restantes resistência medicamentosa. O tempo de seguimento médio foi de 38±16 meses. Conclusão - Os resultados indicaram ser a TVMR arritmia de evolução benigna, sem um substrato anatômico detectável pelos meios diagnósticos de rotina, desencadeada muito provavelmente por mecanismo eletrofisiológico não reentrante e com freqüente resistência medicamentosa. Dos antiarrítmicos utilizados de rotina, este estudo sugere ser o sotalol o mais efetivo
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Tachycardia, Ventricular/physiopathology , Echocardiography , Retrospective Studies , Tachycardia, Ventricular/drug therapy , Electrocardiography , Anti-Arrhythmia Agents/therapeutic use , Exercise TestABSTRACT
PURPOSE--To determine the value of the high-resolution ECG for the differential diagnosis of arrhythmogenic right ventricular disease. METHODS--A group of 33 patients were studied, 16 males, mean age 34 +/- 16 years. All patients presented non-sustained or sustained or repetitive monomorphic ventricular tachycardias, with left bundle branch block morphology. The anatomic and functional evaluation of the right ventricle was made by a previous echocardiogram. No patient presented left ventricular or septal pathology. High-resolution ECG were obtained from a Corazonix-Predictor II program. In the filtered QRS was analyzed root mean square of the last 40ms QRS, the final lasting of the low amplitude signals < 40 microV and filtered QRS duration. Ten patients underwent to electrophysiological study with right ventricular mapping. RESULTS--The ventricular tachycardias was non-sustained in 18 patients, sustained in 8 and repetitive monomorphic in 7 patients. The echocardiogram was normal in 23 patients, and all these also presented normal high resolution ECG. Among the 10 patients with altered echocardiogram, 9 presented abnormal high-resolution ECG (sensibility 90 per cent ; specificity 100 per cent ; positive predictive value 100 per cent ; negative predictive value 96 per cent ; efficacy of the method to define the presence of manifested right ventricular pathology was 96 per cent ). Among the 10 patients with altered echocardiogram, 8 underwent to electrophysiological study. In all was detected an abnormal ventricular mapping and abnormal high-resolution ECG. CONCLUSION--The high-resolution ECG is an useful method to define a right ventricular manifested pathology in presence of arrhythmogenic disease of this cavity