Role of biopsies in patients with residual rectal cancer following neoadjuvant chemoradiation after downsizing: can they rule out persisting cancer?

AIM: The study aimed to determine the value of postchemoradiation biopsies, performed after significant tumour downsizing following neoadjuvant therapy, in predicting complete tumour regression in patients with distal rectal cancer. METHOD: A retrospective comparative study was performed in patients with rectal cancer who achieved an incomplete clinical response after neoadjuvant chemoradiotherapy. Patients with significant tumour downsizing (> 30% of the initial tumour size) were compared with controls (< 30% reduction of the initial tumour size). During flexible proctoscopy carried out postchemoradiation, biopsies were performed using 3-mm biopsy forceps. The biopsy results were compared with the histopathological findings of the resected specimen. UICC (Union for International Cancer Control) ypTNM classification, tumour differentiation and regression grade were evaluated. The main outcome measures were sensitivity and specificity, negative and positive predictive values, and accuracy of a simple forceps biopsy for predicting pathological response after neoadjuvant chemoradiotherapy. RESULTS: Of the 172 patients, 112 were considered to have had an incomplete clinical response and were included in the study. Thirty-nine patients achieved significant tumour downsizing and underwent postchemoradiation biopsies. Overall, 53 biopsies were carried out. Of the 39 patients who achieved significant tumour downsizing, the biopsy result was positive in 25 and negative in 14. Only three of the patients with a negative biopsy result were found to have had a complete pathological response (giving a negative predictive value of 21%). Considering all biopsies performed, only three of 28 negative biopsies were true negatives, giving a negative predictive value of 11%. CONCLUSION: In patients with distal rectal cancer undergoing neoadjuvant chemoradiation, post-treatment biopsies are of limited clinical value in ruling out persisting cancer. A negative biopsy result after a near-complete clinical response should not be considered sufficient for avoiding a radical resection.

Photo-assisted electrochemical degradation of real textile wastewater.

In the present study, photo-assisted electrochemical degradation of real textile wastewater was performed. Degradation assays were performed at constant current (40 mA cm(-2)) in a combined electro/photochemical flow-cell using a Ti/Ru(0.3)Ti(0.7)O(2) DSA type electrode. The results show that the method is capable of removing color and chemical oxygen demand (COD) from the effluent. Additionally, the effect of initial pH and type of supporting electrolyte (Na(2)SO(4) or NaCl) was investigated. The principal figures of merit used in this study were COD removal and color removal (605 nm). The results show that up to 72% color and up to 59% COD removal in 120 min is possible under the operating conditions employed. Studies of the phytotoxicity of the wastewater before and after the photo-assisted degradation assays are also presented and the results demonstrate that the toxicity of the effluent is dependent on the length of electrolysis time and the treatment procedure employed.

Electrical behavior of T-wave polarity alternans in patients with congenital long QT syndrome.

OBJECTIVES: This study was designed to evaluate the incidence and characteristics of onset of T-wave polarity alternans (TWPA) in patients with long QT syndrome. BACKGROUND: The T-wave alternans is a phenomenon that consists of beat-to-beat variability in the amplitude, morphology, and sometimes polarity of the T-wave, and it may trigger life-threatening arrhythmias. METHODS: The 24-h Holter recordings of 11 patients with congenital long QT syndrome were studied. Episodes of TWPA with 10 or more consecutive cycles were selected and analyzed as follows: 1) mean cycle length (MCL) and QTc interval duration (QTcI) of the episodes of TWPA and the 10 cycles preceding and succeeding the TWPA; 2) MCL and QTcI of the third, second, and first minute before onset (Mn_3, Mn_2, Mn_1); 3) MCL and QTcI from the tenth to the first cycle immediately preceding the onset of TWPA (R_10 to R_1); 4) MCL and QTcI from the first to the fourteenth cycle during alternans (R0 to R14); 5) MCL and QTcI from the first to the tenth cycle immediately succeeding TWPA (R+1 to R+10); 6) linear correlation (Lnc) between QT interval and cycle length (CL) (LncQT/CL) during alternans and for the 10 preceding cycles; 7) Lnc between the first three alternans cycles and episode duration (Lnc 3CL/EpD); and 8) difference between the longest and shortest QTc interval. We also selected episodes consisting of four or more consecutive cycles in order to analyze daily rhythms of the phenomenon. RESULTS: The TWPA was observed in 5 (45%) out of the 11 patients studied. The alternans process is initiated by a sudden shortening of the first alternans cycle without previous heart rate changes and ends at the moment when prolongation of the cycle tends to occur. LncQT/ CL-alternans: r = 0.38 +/- 0.2 (p = 0.20); without alternans: r = 0.81 +/- 0.06 (p = 0.01). Lnc 3CL/EpD: r = 0.002 (p = 0.992). The QTc difference during alternans: 312.0 +/- 52.1 ms; without alternans: 86.0 +/- 36.4 ms (p = 0.001). Daily rhythm: 71% of the episodes occurred between 8 AM and 8 PM, with higher incidence during the morning. CONCLUSIONS: The TWPA was dependent on the cardiac CL; there was loss of the LncQT/CL and an increase in the QT interval variability. Like other biological variables, T-wave polarity alternans has a higher density during the morning.

Signal-averaged P wave in patients with Wolff-Parkinson-White syndrome after successful radiofrequency catheter ablation.

OBJECTIVES: We attempted to establish a relation between the atrial conduction time assessed by the signal-averaged P wave electrocardiogram and episodes of paroxysmal atrial fibrillation in patients with the Wolff-Parkinson-White syndrome. BACKGROUND: The incidence of paroxysmal atrial fibrillation is higher in patients with the Wolff-Parkinson-White syndrome than in normal persons. However, the role of intraatrial conduction delay in precipitating the disorganization of atrial rhythm is not completely understood. METHODS: The total duration of the signal-averaged P wave and the P wave in standard lead II was evaluated after successful radiofrequency catheter ablation in 28 patients with the Wolff-Parkinson-White syndrome. The data obtained from 17 patients (61%) with a documented history of prior paroxysmal atrial fibrillation (group I) were compared with those obtained from 11 patients (39%) without a history of atrial fibrillation (group 2). Both groups were further compared with a normal control population. RESULTS: The mean +/- SD signal-averaged P wave duration in group 1 was 141.94 +/- 9.47 ms (range 130.0 to 171.0). Fourteen patients (82%) in this group showed a P wave duration > 135.0 ms. In group 2, the signal-averaged P wave duration was 126.64 +/- 8.72 ms (range 111.0 to 136.0). Only one patient in this group (9%) showed a P wave duration > 135.0 ms (p < 0.000, group 1 vs. group 2). The signal-averaged P wave duration in the control group was 124.46 +/- 4.49 ms (range 115.0 to 129.5; p < 0.000, group 1 vs. the control group; p < 0.454, group 2 vs. the control group). The P wave duration in lead II was 92.06 +/- 8.85 ms in group 1 and 92.27 +/- 7.86 ms in group 2 (p < 0.949). Using a cutoff value of < 135.0 ms for a normal signal-averaged P wave duration, the method had a sensitivity and specificity and positive and negative predictive values of 82%, 91%, 93% and 77%, respectively, for identifying patients with clinical paroxysmal atrial fibrillation. CONCLUSIONS: In the current study, the signal-averaged P wave showed a prolonged intraatrial conduction time in patients with the Wolff-Parkinson-White syndrome and paroxysmal atrial fibrillation. These patients can be differentiated from those with the pre-excitation syndrome without clinical atrial fibrillation as well as from normal subjects. The prolonged intraatrial conduction time may serve as an atrial substratum for development and maintenance of the fibrillatory state.

[Torsades de pointes: analysis of 105 episodes]. / Torsades de pointes: análise de 105 episódios.

PURPOSE: To analyze episodes of Torsades de Pointes (TP), in search of its electrocardiographic characteristics. PATIENTS AND METHODS: We analyzed 105 episodes of TP, in 4 patients using quinidine and diuretics, recorded by 24-hour Holter monitoring. The following parameters were studied; ventricular repolarization out of TP, rhythm disturbances before TP; ECG characteristics of the onset, the bouts and the end of the TP. RESULTS: Ventricular repolarization, out of the TP, was abnormal, with the presence of U-waves at the end of the T-waves, resulting in prolongation of the QT (QU) interval. The U-wave voltage was noted to be cycle-length dependent. Ventricular bigeminy preceded TP in 100 episodes (95%) and the mean interval between both parameters was 18 +/- 16 min. The onset of the TP episodes showed the "short/long/short cycle rule", hereby called "pre-pause cycle", "preparing cycle" and "trigger cycle" respectively. The rotatory QRS-T morphology around the baseline, was seen in 75% of episodes, at the beginning or throughout the bout. Monomorphic ventricular tachycardia pattern was seen in the other 25% of episodes. Termination of bouts was sudden in all cases, and persistent ventricular bigeminy led to another bout in 90 episodes (85%). CONCLUSION: In TP patients, there is enlargement of QT intervals mostly due to U-waves appearance. The U-waves seen in these cases, probably have an important role in the genesis of TP and are probably related to ventricular after-potentials (triggered activity). Ventricular bigeminy is a premonitory sign of TP in patients using class 1A antiarrhythmic drugs. Persistent ventricular bigeminy post-TP episodes is a strong indicator of another bout of TP. The onset of TP is more important than its morphology for the correct diagnosis of this arrhythmia.

[High-resolution P-wave electrocardiogram in patients with a history of paroxysmal atrial fibrillation]. / O eletrocardiograma de alta resolução da onda P em pacientes com história de fibrilação atrial paroxística.

PURPOSE: To study by using the signal-averaged P wave, the atrial activation of patients with documented episodes of paroxysmal atrial fibrillation (PAF). METHODS: This study enrolled a total of 20 patients with documented episodes of paroxysmal atrial fibrillation (males 14; mean age 58.4 +/- 10.6 years). The signal-averaged P wave was recorded with a Corazonix Predictor II system. The total P wave duration was determined from the combined filtered x,y,z vector-magnitude and used for analysis. The results were compared with a normal group of 10 patients, matched in age. RESULTS: In the control group, the total P wave duration ranged from 120.0 to 135.0 (mean = 128.3 +/- 5.8) ms. In the group of PAF, the total P wave duration ranged from 118.0 to 168.5 (mean = 151.5 +/- 13.7) ms (p < 0.000). Sixteen (80%) of this patients showed a P wave duration > 140.0 ms. With a cut < 140.0 ms for the normal atrial activation, the sensitivity was 76%, specificity was 100%, positive and negative predictive value were 100% and 60% respectively for the method detected patients with PAF. CONCLUSION: Patients with PAF showed a prolonged signal-averaged P wave duration and should be differentiated by this method from the normal population.

[R-R variability in acute anterior infarct after thrombolytic therapy]. / Variabilidade de R-R no infarto agudo anterior após a terapêutica trombolítica.

PURPOSE: To analyse the effects of thrombolysis on the integrity of the autonomic nervous system, in patient with acute myocardial infarction (AMI) of the anterior wall, using the determination of the heart rate variability. METHODS: We prospectively evaluated the R-R variability of the 31 consecutive patients with anterior AMI submitted to coronary thrombolysis (25 males; mean age 59 +/- 14 years) from Holter tapes. An algorithm in a 286 computer program was used for heart rate variability (HRV). With this system, R-R variations during sinus rhythm and for a five consecutive minutes periods was determined. The results were expressed as the mean of the total determined periods; the standard deviation of the mean of all determined periods and the mean of the standard deviation. The reperfusion criteria was the early enzymatic rise of the CKMB activity levels (< or = 12 h) combined with a 50% or more reduction in the ST segment elevation within the first hour after thrombolytic therapy and the presence of an accelerated idioventricular rhythm at the same time. The reperfused group (group 1 = 16 patients) and non-reperfused group (group 2 = 15 patients) were compared in terms of R-R variability. RESULTS: Mean R-R: group 1 = 716 +/- 84 ms (540-820 ms); group 2 = 595 +/- 115 ms (390-870 ms)-p < 0.02. ms (34-92 ms); group 2 = 50 +/- 14 ms (23-77 ms)-p < 0.01. HRV 50 ms: group 1 = 2 patients; group 2 = 5 patients. Means SD of the R-R: group 1 = 44 +/- 14 ms (26-65 ms); group 2 = 39 +/- 17 ms (19-69 ms)-p: ns. CONCLUSION: Patients with anterior AMI and thrombolytic therapy demonstrate greater HRV; this finding suggested better integrity of the autonomic nervous system, with possible effects on prognosis.

[Antiarrhythmic drug effectiveness. Proposal for a new approach based on pharmacological hourly effects]. / Efficácia das drogas antiarrítmicas. Proposta para uma nova forma de avaliação baseada nos efeitos farmacológicos horários.

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.

[Contribution of dynamic electrocardiography by Holter monitoring in the evaluation of congenital long QT syndrome patients]. / Contribuição de eletrocardiografia dinâmica pelo sistema Holter na avaliação de pacientes com a síndrome congênita do QT longo.

PURPOSE: The purpose of this study was to evaluate the value of ambulatory electrocardiogram as a clinical tool to assess ventricular repolarization in patients with the congenital long QT syndrome. METHODS: The study population comprised six patients and their data were compared to a control group of six patients matched in age and gender. The QT interval (ms), corrected by the heart rate, was measured in the first minute of each hour using two monitoring leads, with the mean of six consecutive complexes. The data obtained include the morphologic pattern of T wave, the mean 24-h QTc interval, relation between QT and cardiac cycle, QTc variability (assessed calculating hourly standard deviation of the interval and then obtaining the global 24-h mean), QTc dispersion (difference between the longest and shortest QTc interval). RESULTS: In all patients abnormal patterns of T waves were detected with frequent episodes of T wave alternans. Mean 24-h QTc--patients: 598.2 +/- 73.8 ms; controls: 436.1 +/- 8.9 ms (p = 0.000). Linear correlation and regression between QT and heart rate-patients: r = 0.812; controls: r = 0.967 (p = 0.000). QTc variability-patients: 36.9 +/- 17.2 ms; controls: 14.7 +/- 2.1 ms (p = 0.01). QTc dispersion-patients: 168.3 +/- 70.2 ms; controls: 53.3 +/- 8.1 ms (p = 0.000). CONCLUSION: The data showed increased hourly QTc variability. QTc dispersion and worse correlation between QT and heart rate. This data may reflect an abnormally augmented ventricular vulnerability.

[Evaluation of the ventricular arrhythmogenic profile of patients with dilated cardiomyopathy and reduced ejection fraction]. / Avaliação do perfil arritmogênico ventricular de pacientes com miocradiopatia dilatada e fralcão de Ejeção diminuída.

PURPOSE: To evaluate the arrhythmogenic profile of patients with dilated cardiomyopathy of low ejection fraction and its prognostic significance. METHODS: Data from 40 patients (30 males; mean age: 52 +/- 13 years) were analysed including ventricular arrhythmias (24h - Holter monitoring), autonomic balance from heart rate variability in time domain (rMSSD and pNN50 indexes), ventricular late potentials (signal averaged electrocardiogram (ECG) and dispersion of ventricular repolarization measured from 12-lead ECG. RESULTS: There was a high prevalence of ventricular arrhythmias with at least one episode of nonsustained ventricular tachycardia (VT) in 60% of the patients. Depressed vagal activity was observed in more than half of the patients. In only 30% of the patients the signal-averaged ECG was positive. The dispersion of ventricular repolarization ranged from 20 to 100 ms. The presence of > 30 ventricular premature beats or nonsustained VT on Holter monitoring was the most significant predictor of cardiac death and sudden cardiac death with a relative risk of 1.9 and 3.2, respectively (p = 0.01 and 0.000). CONCLUSION: In this study population it was noted that patients with dilated cardiomyopathy and low ejection fraction had an abnormal electrical and autonomic cardiac behaviour. These findings could represent risk factors for the occurrence of life-threatening arrhythmias or fatal events.

[Cardiac memory in patients with permanent artificial pacemakers]. / Memória cardíaca em pacientes com marcapasso artificial definitivo.

PURPOSE: To correlate the direction of QRS complex of paced beats and postpacing T wave, in patients with artificial pacemaker. METHODS: Thirty five patients with spontaneous rhythm obtained by chest wall stimulation or by programmability of the automatic interval. It was correlated in all patients, the direction forces of QRS complexes of paced beats and postpacing T waves in all 12 ECG leads. It was considered as a cardiac memory phenomenon when QRS complexes of paced beats and postpacing T waves had the same polarity. The phenomenon was correlated with the 12 ECG leads and with specific variables like spontaneous rhythm, QRS complex duration, type and modality of artificial stimulation and chronicity of the implant. RESULTS: The artificial QRS complexes and spontaneous T waves had the same direction in 5 or more leads of the frontal plane in 77% of the patients and in 50% of the patients in the horizontal plane. In patients with supraventricular command, this correlation was found in 82% of the patients and in 50% of the patients with idioventricular rhythm. Regardless of the type of spontaneous command, the phenomenon was better observed with normal intraventricular conduction. It was not found correlation between type, modality of stimulation and chronicity of the implant and cardiac memory. It was better observed in aVF, D2, D3 and V3, V4. CONCLUSION: The phenomenon of cardiac memory in patients with artificial pacemaker is very frequent. The most important factor to develop the phenomenon seem to be a normal pattern of ventricular activation.

Arrhythmogenic cardiomyopathy of the right ventricle. Predictive value of QT interval dispersion to assess arrhythmogenic risk and sudden death.

OBJECTIVE: To determine in arrhythmogenic right ventricular cardiomyopathy the value of QT interval dispersion for identifying the induction of sustained ventricular tachycardia in the electrophysiological study or the risk of sudden cardiac death. METHODS: We assessed QT interval dispersion in the 12-lead electrocardiogram of 26 patients with arrhythmogenic right ventricular cardiomyopathy. We analyzed its association with sustained ventricular tachycardia and sudden cardiac death, and in 16 controls similar in age and sex. RESULTS: (mean +/- SD). QT interval dispersion: patients = 53.8+/-14.1 ms; control group = 35.0+/-10.6 ms, p = 0.001. Patients with induction of ventricular tachycardia: 52.5+/-13.8 ms; without induction of ventricular tachycardia: 57.5+/-12.8 ms, p =0.420. In a mean follow-up period of 41+/-11 months, five sudden cardiac deaths occurred. QT interval dispersion in this group was 62.0+/-17.8, and in the others it was 51.9+/-12.8 ms, p = 0.852. Using a cutoff > or =60 ms to define an increase in the degree of the QT interval dispersion, we were able to identify patients at risk of sudden cardiac death with a sensitivity of 60%, a specificity of 57%, and positive and negative predictive values of 25% and 85%, respectively. CONCLUSION: Patients with arrhythmogenic right ventricular cardiomyopathy have a significant increase in the degree of QT interval dispersion when compared with the healthy population. However it, did not identify patients with induction of ventricular tachycardia in the electrophysiological study, showing a very low predictive value for defining the risk of sudden cardiac death in the population studied.

[The electrocardiogram of high resolution during ventricular tachycardia]. / O eletrocardiograma de alta resolução durante taquicardia ventricular.

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.

[Study of the autonomic behavior of escape rhythms in congenital atrioventricular block]. / Estudo do comportamento autonômico dos ritmos de escape no bloqueio atrioventricular congênito.

PURPOSE: To study the autonomic behavior of the escape rhythm in congenital complete heart block (CCHB), using heart rate variability (HRV). METHODS: A group of 10 asymptomatic patients with CCHB and narrow QRS was studied, 7 females; mean age = 14 +/- 9 years. The following time domain indexes were analyzed from a 24 hour Holter monitoring. The mean of all RR intervals (NN); the standard deviation of the mean (CLV5); the mean of all standard deviations (SDNN); the percent of successive differences longer than 50 ms (pNN50); the shortest cycle (CC) and the longest cycle (CL). The results were compared with a control group, using the Wilcox test for statistical analysis. RESULTS: The results were: NN = 1016 +/- 276 ms in CHB and 725 +/- 121 ms in control (p < 0.01); CLV5 = 184 +/- 97 ms in CHB and 125 +/- 38 ms in control (p = NS); SDNN = 102 +/- 32 ms in CHB and 88 +/- 29 ms in control (p = NS); rMSSD = 113 +/- 69 ms in CHB and 78 +/- 28 ms in control (p = NS); pNN50 = 43 +/- 26% in CHB and 33 +/- 12% in control (p = NS); CC = 582 +/- 129 ms in CHB and 333 +/- 49 ms in control (p = 0.05). CONCLUSION: No statistical difference was noted by comparing HRV indexes in CHB with control subjects, showing that the autonomic behavior of the escape rhythm in CCHB is similar to the sinus node in asymptomatic patients. The differences in NN, CC and CL are probably related to intrinsic properties of each command.

[Repetitive monomorphic ventricular tachycardia]. / Taquicardia ventricular monomórfica repetitiva.

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.

[Incessant supraventricular tachycardia. Retrospective study of 13 patients]. / Taquicardias supraventriculares incessantes. Estudo retrospectivo de treze pacientes.

PURPOSE: To evaluate, retrospectively, the main clinical findings observed in patients with incessant supraventricular tachycardias. METHODS: Data from 13 patients were analyzed, 8 men and 5 women, mean age 24 +/- 19 years. All patients underwent to periodic clinical evaluation with serial ECG, Holter, echocardiography and in three patients an electrophysiological study. From these diagnostic methods it was possible to define the site of origin of the tachycardias, the autonomic influences upon them, the progressive hemodynamic compromise leading to tachycardiomyopathy and the drug response. RESULTS: In 9 patients the tachycardias had an atrial origin, in three an accessory pathway was involved and in one patient an atypical nodal reentry was identified. Clear autonomic influences upon the rate of the tachycardias were noted in the majority of patients, based on Holter recordings. Forty-six percent of the population developed progressive contractile deficit, contributing in one patient to his death. Drug failure was observed in 62% of patients, even with the use of three antiarrhythmic drugs in a row. The large majority of the patients were still asymptomatic by the time of the retrospective data. CONCLUSION: The most relevant clinical aspects are the progressive development of tachycardiomyopathy, associated with refractoriness to drug therapy and indicate in this population the approach to be undertaken.

[High-resolution electrocardiography in arrhythmogenic right ventricular disease]. / Electrocardiografia de alta resolução na doença ventricular direita arritmogênica.

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%; specificity 100%; positive predictive value 100%; negative predictive value 96%; efficacy of the method to define the presence of manifested right ventricular pathology was 96%). 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.

[Efficacy of sotalol in idiopathic ventricular arrhythmia originating in the right ventricular outflow tract]. / Eficácia do sotalol nas arritmias ventriculares idiopáticas com origem em trato de saída de ventrículo direito.

PURPOSE: To evaluate the effects of sotalol in patients (pts) with idiopathic 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 circadian 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.

[Torsades de Pointes: analysis of 105 episodes]. / Torsades de Pointes: análise de 105 episódios.

PURPOSE: To analyze episodes of Torsades de Pointes (TP), in search of its electrocardiographic characteristics. PATIENTS AND METHODS: We analyzed 105 episodes of TP, in 4 patients using quinidine and diuretics, recorded by 24-hour Holter monitoring. The following parameters were studied; ventricular repolarization out of TP, rhythm disturbances before TP; EKG characteristics of the onset, the bouts and the end of the TP. RESULTS: Ventricular repolarization, out of the TP, was abnormal, with the presence of U-waves at the end of the T-waves, resulting in prolongation of the QT (QU) interval. The U-wave voltage was noted to be cycle-length dependent. Ventricular bigeminy preceded TP in 100 episodes (95%) and the mean interval between both parameters was 18 +/- 16 min. The onset of the TP episodes showed the "short/long/short cycle rule", hereby called "pre-pause cycle", "preparing cycle" and "trigger cycle" respectively. The rotatory QRS-T morphology around the baseline, was seen in 75% of episodes, at the beginning or throughout the bout. Monomorphic ventricular tachycardia pattern was seen in the other 25% of episodes. Termination of bouts was sudden in all cases, and persistent ventricular bigeminy led to another bout in 90 episodes (85%). CONCLUSION: In TP patients, there is enlargement of QT intervals mostly due to U-waves appearance. The U-waves seen in these cases, probably have an important role in the genesis of TP and are probably related to ventricular after-potentials (triggered activity). Ventricular bigeminy is a premonitory sign of TP in patients using class 1A antiarrhythmic drugs. Persistent ventricular bigeminy post-TP episodes is a strong indicator of another bout of TP. The onset of TP is more important than its morphology for the correct diagnosis of this arrhythmia.

Colonoscopic polypectomy.

A total of 87 polyps were treated during 62 colonoscopic examinations on 60 patients; 69 polyps were resected and 18 were fulgurated with the hot-biopsy forceps. Fifteen patients were under 13 years old, and the average age was 38 years. Twelve patients had more than one polyp. There were no complications and the method could be carried out in all patients, whenever it was indicated. Sixteen polyps were hamartomas, 13 shistosomatic, six hyperplastic, two lymphoid and 36 adenomas. Among these adenomas, six showed evidence of foci carcinoma, one in situ and five, invasive. Surgical resection was indicated in only one patient with sessile polyp with invasive focus of carcinoma. No metastasis was detected whatsoever.