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D Bonhorst

Publications and source records attributed to D Bonhorst.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Value of "cardiac event recorders" in the assessment of sporadic cardiac symptoms].

OBJECTIVES: To determine the value of the Cardiac Event Recorder (CER) in the diagnosis and treatment orientation of bradydysrhythmias, tachydysrhythmias and ischaemic events, based on our experience at the Santa Cruz Hospital. METHODS: We retrospectively analysed 100 consecutive patients tested with a CER between January 1990 and December 1996 (mean follow-up, 272 +/- 202 days); the mean age of the patients (66 women and 34 men) was 45 +/- 18 years (range: 7 to 83); structural cardiac disease was present in 34% of the patients. CER was indicated for the investigation of symptoms suggestive of bradydysrhythmias (pre-syncope and/or syncope)--Group B--in 24 patients, tachydysrhythmias (palpitations and/or tachycardia sensation)--Group T--in 72 patients and ischaemic events--Group I--in the remaining four patients. We compared these groups with respect to demographic characteristics, prevalence of structural cardiac disease and efficacy of the test in the investigation of symptoms; periodicity of symptoms and duration of CER testing were analysed. In patients that experienced typical symptoms during the test, we analysed the electrocardiogram recorded at the time of the event and we investigated whether abnormal ECG findings influenced the therapeutic approach and whether this led to better symptomatic outcome. RESULTS: Patients in groups B and T were mainly women (54 percent vs 74 percent, NS). Group B patients were older than group T patients (mean age, 56.4 +/- 17.8 vs 40.0 +/- 16.0 yrs, P < 0.001). In group B, structural cardiac disease was less prevalent (37.5% vs 78.0%, P < 0.001) and symptom periodicity was greater (weekly: 12.5% vs 78.0%, monthly: 87.5% vs 15.2%, P < 0.001) than in group T. Duration of CER testing and number of events recorded were similar in the two groups. In both, CER testing was an important aid for therapeutic approach. Twenty two patients (eight B, 13 T and one I) had no typical symptomatic episodes during the CER test; in the remaining 78 patients (16 B, 59 T and three I), an electrocardiogram recording during such episodes was available for analysis. The ECG was abnormal in 44 of these patients, 12 (75%) being of group B and 32 (54%) of group T. Symptom periodicity was a few weeks in 65% of all patients (6 B, 57 T and two I). Duration of CER testing was < or = two weeks in 91 percent of the patients (22 B, 65 T and four I). CER testing guided the therapeutic approach in 78% of all patients. Changes of treatment strategy were more frequent in patients with CER documented typical symptomatic episodes than in those without (46% vs 9%, P < 0.02). When changes of treatment occurred, symptomatic outcome was better (97% vs 55%, P < 0.001). CONCLUSIONS: The CER is an important guide for the diagnostic and therapeutic approach for patients with intermittent arrhythmia suggesting, symptoms (78% of patients). A recording of normal ECG during typical symptoms reassures the patient and excludes potentially toxic treatments. Our selection of patients for CER testing seemed adequate since most typical symptomatic events occurred during the first two weeks of the test; longer duration of CER testing seems unnecessary.

Adolescent↗
PubMed1996

[Implantable cardioverter-defibrillators in patients resuscitated from sudden death and in patients with sustained refractory ventricular tachycardia].

OBJECTIVE: The aim of this study was to evaluate the results of our experience with implantable cardioverter-defibrillator therapy. PATIENT SELECTION: We treated with implantable cardioverter-defibrillator (ICD) 18 patients, 15 male and 3 female, mean age 51 years, ranging from 12 to 76 years, with life threatening ventricular arrhythmias. Eleven patients were resuscitated from cardiac arrest and seven had refractory ventricular tachycardia. The underlying condition was coronary artery disease in 12 patients, dilated cardiomyopathy in two, congenital long QT syndrome in one, mitral regurgitation in one and idiopathic in two patients. METHODS: All patients underwent cardiac catheterization and electrophysiological study before ICD implantation. In the first patient epicardial leads were used, but a transvenous approach was used in the remaining 17 patients. The device was implanted in an abdominal position in all patients. Defibrillation and pacing threshold tests were performed during the implantation procedure and whenever necessary. After implantation, patients were followed up in an outpatient basis, with evaluation of therapy efficacy and reprogramming of the device if required. The mean follow-up time was 16 months, ranging from 1 to 40 months. RESULTS: The implantation was successful and without complications in all patients. Defibrillation threshold was considered within normal range, with an electrode impedance ranging from 40 to 65 Ohms. During the follow-up period no deaths occurred, 8 patients (44%) had episodes of VT or VF that were successfully treated, with shock in six patients, with antitachycardia pacing in one and with both modalities in another patient. Inappropriate shocks were observed in three patients (16%). The device was reprogrammed in five patients. CONCLUSIONS: Our experience with implantable ICD in patients who survived cardiac arrest or with refractory VT has shown a low surgical risk with no mortality. The incidence of ICD discharges was high, with a satisfactory efficacy rate and the number of inappropriate shocks was acceptable. The careful patient selection made possible a good cost/benefit relation.

Adolescent↗
PubMed1996

[The radiofrequency catheter ablation of occult accessory atrioventricular pathways].

OBJECTIVE: The aim of this study was to evaluate our results of radiofrequency catheter ablation (RFCA) of concealed accessory atrioventricular pathways (CP). PATIENT SELECTION: We treated with RFCA 19 patients, with 21 CP, 10 men and 9 women, mean age 37 +/- 16 years, with supraventricular tachycardia (SVT) and absence of ventricular pre-excitation in the electrocardiogram (ECG). These patients comprised 50% of the patients who underwent RFCA for SVT and had no ventricular pre-excitation in the ECG. The diagnosis of CP was made by electrophysiologic study, based on the demonstration of a pathway capable of retrograde conduction only. METHODS: The RFCA was performed without antiarrhythmic drugs in the same session of the electrophysiologic diagnosis. The location of the CP site was obtained by catheter mapping, looking for the earliest atrial retrograde activation during tachycardia or ventricular pacing. RESULTS: The CP had a right-sided location in only 2 patients who had an incessant form of SVT, the CP in these patients exhibit decremental conduction--permanent junctional reciprocating tachycardia. In the other patients the CP was left-sided, lateral in 11 patients, posterior in 3, postero-septal in 3 and medial septal in one patient. In 9 patients there was a simultaneous ventricular activation in the his bundle electrogram and in the electrogram of the ablation site, suggesting partial anterograde penetration of the stimuli on the accessory pathway. Success criteria were achieved in 18 patients (95%) corresponding to 20 CP. CONCLUSIONS: The prevalence of CP in the presence of SVT without ventricular pre-excitation is high, almost all left-sided. The CP displays eccentric atrial activation during SVT. It is possible that CP are capable of partial anterograde conduction as well. The success rate of RFCA is high.

Adolescent↗
PubMed1996

[The radiofrequency catheter ablation of ventricular tachycardia].

OBJECTIVE: The aim of this study was to evaluate our results of radiofrequency catheter ablation (RFCA) of ventricular tachycardia. PATIENT SELECTION: We treated with RFCA nine patients, six male and three female, mean age 36 +/- 12 years with ventricular tachycardia (VT), who fulfilled the following criteria; 1) recurrent VT; 2) resistant fo medical therapy despite the use of more than one antiarrhythmic drug; 3) inducible by programmed ventricular stimulation; 4) hemodynamically well tolerated. The VT etiology was coronary artery disease (CAD) in three patients, dilated cardiomyopathy in one, right ventricular dysplasia in one and it was idiopathic in four (being fascicular in three and catecholaminergic right ventricular outflow tract VT in one). METHODS: The RFCA was performed under antiarrhythmic medication. The adequate ablation site was obtained by mapping of the VT, looking for the earliest ventricular activation, identification of isolated mid-diastolic potentials during sinus rhythm or presystolic during VT, good pace mapping (at least 10 of the 12 standard ECG leads), and high frequency short duration spikes, the so called P potentials in fascicular VT. Primary success achieved when occurred termination of VT during application of RF energy and/or VT was no longer inducible by programmed stimulation with the same stimulation protocol. RESULTS: Global primary success rate was 89%, being 100% in idiopathic VT, and 80% in VT associated with structural heart disease. In a follow-up period of 12 +/- 14 months all patients were alive, 75% free of VT in the idiopathic VT group; and 50% in patients with structural heart disease. One of these patients underwent cardioverter defibrillator implantation to treat a fast VT with a new morphology not treated by ablation, and the other two had VT modification with a significant reduction in the number of episodes. CONCLUSIONS: Radiofrequency catheter ablation of VT has shown a good success rate, and it is a valuable alternative in patients with hemodynamically tolerable VT, refractory to drug treatment, highly symptomatic and without surgical indication. In cases of idiopathic VT we had a high rate success and we think that RFCA will probably become the primary indication in symptomatic patients.

Adult↗
PubMed1996

[Holter electrocardiography en pediatric cardiology: preliminary experience].

PURPOSE: Evaluation of the diagnostic value of continuous electrocardiographic recording (Holter monitoring) in Paediatric Cardiology. STUDY DESIGN: Retrospective study based on the data records of the Arrhythmia Department regarding patients with less than 20 years of age with Holter monitoring performed between January 1983 and February 1995 (374 recordings). PATIENTS: 277 patients were studied, 163 were male and 114 female with a mean age of 12 +/- 5 years. Heart organic anomalies were present in 155 patients and 92 patients had previous cardiac surgery with cardiopulmonary bypass. Clinical indications for Holter recording were the evaluation of symptoms related to arrhythmias (38%), documented dysrhythmia (23%), arrhythmia detected on physical examination (18%) and evaluation of risk in patients without symptoms of arrhythmia (17%). METHODS: Holter recordings were performed during 24 hours with two channels (modified V1 and V5). RESULTS: Significant rhythm and conduction disturbances were found in 122 patients. These were ventricular premature complexes > or = 10/hour (27 patients), AV block (25 patients) and supraventricular premature complexes > or = 10/hour (22 patients). Holter recording revealed significant dysrhythmias in 52% of patients with previously documented dysrhythmia, in 43% of patients referred for assessment of risk without symptoms of arrhythmia, provided insight in 48% of requests due to arrhythmia detected on physical examination and 24% of requests for symptoms related to arrhythmias. In 13 patients the results of Holter recording led to therapeutic or diagnostic measures. CONCLUSIONS: Holter recording showed an overall sensitivity of 44% in the detection of significant arrhythmias and led to therapeutic and additional diagnostic measures in 11% of these patients. Holter recording seems to provide important information in the evaluation of arrhythmias in the paediatric age group.

Adolescent↗
PubMed1996

[Exertion syncopal crisis in the young, associated with idiopathic long QT syndrome].

The cases of two young patients with repetitive syncopal attacks due to idiopathic long QT syndrome (ILQTS) are reported. Both had been primarily misdiagnosed for seizures. In one of the cases the QT interval in the ECG at rest was normal. The same patient had a previous episode of cardiac arrest with ventricular fibrillation. The treadmill stress test was of great value, revealing polymorphic ventricular tachycardia induced by exercise, and evaluating the efficacy of beta-blocking therapy in the follow-up. The ILQTS should be considered a possible etiology in any patient presenting with new onset seizures, especially in the young. The treatments were different in both cases. In the first one, the treatment with nadolol (100 mg od) revealed to be very effective with total remission of symptoms. The treadmill stress test performed 15 days after the beginning of treatment did not show any ventricular arrhythmias, and it was assumed that the patient was effectively protected against ventricular arrhythmias. After 4.5 months of follow up, no syncopal episodes occurred. In the second case due to young age, the frequency, and the severity of the attacks (cardiac arrest with ventricular fibrillation), and the inefficacy of beta-adrenergic-blocking agents, the implantable cardioversor-defibrillator was the treatment chosen, although the beta blocking therapy was maintained to reduce the number of arrhythmic events. The ILQTS is a rare anomaly related to sudden cardiac death. The ILQTS is characterised by the association of several distinctive electrocardiographic features, among which prolongation of the QT interval is the best known. Life-threatening arrhythmia occurs usually under conditions of physical or psychological stress. Relatively effective therapies do exist and are represented by antiadrenergic interventions: beta-adrenergic-blocking agents are the treatment of choice. When they fail, left sympathetic denervation or the automatic implantable cardioversor-defibrillator have also proved to be effective.

Adult↗
PubMed1996

[Acute myocardial infarct in a young cocaine user].

In patients less than 40 years of age, acute myocardial infarction (AMI) has special clinical and pathophysiologic characteristics. Its prevalence varies between 5 and 10%. In such patients, AMI associated with chronic cocaine abuse has a non-negligible prevalence of 6%. The purpose of this report is to describe the case of a 24-year old male patient with smoking habits and chronic abuse of cocaine and hallucinogenic drugs. This patient developed clinical, enzymatic and electrocardiographic criteria of anterior AMI, two hours after the ingestion of an LSD-like hallucinogenic drug. The coronary angiography revealed a critical stenosis of the medium segment of the left anterior descendent artery, and a pre-stenotic aneurysmatic dilatation. In order to determine the etiology of the aneurysm, various laboratory and histologic tests were performed. The results of these were normal. We review the pathophysiology, clinical manifestations and prognosis of cocaine-associated AMI.

Adult↗
PubMed1996

[Experience with dl-sotalol in the treatment of supraventricular arrhythmia].

OBJECTIVES: To review the results of our experience with oral dl-sotalol for preventive treatment of supraventricular tachyarrhythmias (atrial fibrillation and paroxysmal supraventricular tachycardia). POPULATION: 51 patients, 28 female and 23 male, mean age 46.2 +/- 14.4 years, from outpatient arrhythmology clinics of our institution, with recurrent supraventricular tachyarrhythmias (atrial fibrillation in 24 patients and paroxysmal supraventricular tachycardia in 27). All the patients, but one, had normal left ventricular function. Dl-sotalol was first choice medication in only three patients. Previously 2 +/- 1.3 antiarrhythmic drugs had been used. METHODS: Retrospective evaluation of therapeutic response (number of clinical recurrences according to a semi-quantitative scale) and secondary effects of dl-sotalol during a minimum follow-up of 18 months. The mean daily dose was 205 +/- 90 mg (80 to 400 mg). RESULTS: In 37% of the patients there were no clinical recurrences of arrhythmia during follow-up. In 37% of the patients there was a significant reduction in recurrences. In 26% there was no change in the number of recurrences. There were no significant differences in response between patients with atrial fibrillation and those with paroxysmal supraventricular tachycardia. Secondary effects occurred in 16% of the patients: symptomatic bradycardia, asthma or sexual dysfunction. No patient had heart failure, torsades de pointes, syncope or death. CONCLUSIONS: From our experience, DL-sotalol seems to be a good therapeutic alternative for the preventive treatment of supraventricular tachyarrhythmias, with a low risk in patients with good ventricular function.

Adult↗
PubMed1995

[The evolution of the arterial pressure during a stress test in patients with hypertrophic myocardiopathy].

OBJECTIVES: To study the exercise blood pressure response in patients with hypertrophic cardiomyopathy (HC) and its relationship with sudden death. DESIGN: Retrospective study. POPULATION: We studied 51 patients (P) with HC: 18 women and 33 men. Their average age was 45 +/- 14 years, with a mean follow-up of 55 +/- 37 months. METHODS: Every patient had been subjected to a treadmill stress-test, a 24-hour Holter monitoring and an echocardiographic examination. Particular emphasis was given to blood pressure increments (BPI) during stress-test, the existence of premature ventricular contractions with a frequency of 10 or more per hour (PVC > or = 10), the occurrence of couplets (C) and/or non-sustained ventricular tachycardia (NSVT) on a 24-hour Holter. Finally, the finding of systolic anterior motion (SAM) of the mitral valve, in the routine echocardiogram, was valued. RESULTS: Four patterns of BPI were identified: "1": normal evolution (27 P); "2": plateau type increment (16 P); "3": fall in blood pressure during exercise (6 P); "4": abnormal BPI during recovery (2 P). Two groups were considered: group N-normal BPI, group A-patients with abnormal blood pressure responses. There were no significant differences among therapeutic agents, between the two groups, when the stress-test was performed. SAM was found in 21 P. Only 8 P registered ventricular arrhythmias, half of them with NSVT. No statistical relations were found between BPI and P age, the presence of SAM, PVC > or = 10, C, or NSVT. We found 78% of P in group N in NYHA class I. In contrast, in group A only 46% were in class I (p = 0.04). Only one death, of non cardiac cause, occurred (group A). CONCLUSIONS: There is a large number of patients with HC and abnormal BPI. This is, seemingly, not influenced either by a dynamic left ventricular gradient or by ventricular ectopic beat occurrence. However, a relation appears to exist between the abnormal response and functional class, not explained by the usual (noninvasive) clinical tests.

Adult↗
PubMed1995

[Atrial fibrillation: anticoagulation or antiaggregation. Is there still a controversy?].

Unlike what happened regarding rheumatic atrial fibrillation, there was no consensus until few years ago about the indication for antithrombotic therapy in nonrheumatic atrial fibrillation. Nevertheless, as it was noticed a high prevalence of stroke in this last situation, several clinical trials were accomplished to clarify the role of those drugs. It was reviewed the five initial big trials, which in spite of having different dimensions, endpoints and design, were remarkably consistent in their results, showing in those patients taking varfarine a 60% reduction in ischemic stroke and systemic embolism. Those results were obtained with an acceptable risk of hemorrhage, which was related to anticoagulation intensity. An European trial showed similar results in secondary prevention, in patients with higher risk, all of them with a previous minor stroke. In some of those trials antiplatelet therapy was also evaluated but only one (SPAF I), showed a significant reduction of stroke with aspirin; the reductions of risk was meanwhile much smaller than with varfarine. As there were a high number of patients with indication for anticoagulants one tried to find thromboembolic risk factors, to identify the population potentially more prone to benefit from that therapy. It was possible in SPAF I trial to find some clinical and echocardiographic risk factors. SPAF II trial directly compare aspirine with varfarine, showing the superiority of the last one but also its greater haemorrhagic risk. That study permitted a better understanding of the indications of those two therapies, according to embolic and haemorrhagic risk of each patient.

Atrial Fibrillation↗
PubMed1995

[Antiarrhythmic agents: current situation].

Cardiac Arrhythmia Suppression Trial (CAST) had a profound impact on the practice of cardiology. This trial showed the importance of placebo controls in judging the effects of therapy and the pitfalls of using surrogate end points for mortality in clinical disorders. The number of new prescriptions of class I drugs fell progressively after CAST; there was a change in antiarrhythmic drug labelling as well as on research and the "suppression hypothesis" was no more valuable as a theoretical support to the antiarrhythmic treatment of prognostical significant ventricular arrhythmias. Several arguments favour generalization of CAST results to the whole class I drugs. So, all those drugs depress cardiac conductivity, which is potentially arrhythmogenic, and the results of several trials and overviews are in consonance with CAST ones. Beta-blockers are the sole drugs that consistently decreased cardiac sudden death after myocardial infarction. An ancillary study from CAST trial suggests that those drugs can have also an anti-proarrhythmic effect, which needs further confirmation. Beta-blockers can join an important place in malignant ventricular arrhythmias therapy, used lonely or specially in association with drugs from other classes. CAST conclusions are probably not applicable to class III drugs, as they do not depress conductivity, acting mainly by prolonging repolarization. So, they are the most promising drugs in post CAST era: some trials seem to confirm the advantages of amiodarone and DL-sotalol in clinical use, and there are several other new class III drugs in development. A few little and medium dimension amiodarone trials showed a decrease in mortality in myocardial infarction survivors and in patients with cardiac insufficiency. We are waiting the results of some large trials to get more definitive conclusions. In malignant ventricular arrhythmias, empiric amiodarone have been superior to electrophysiological guided therapy. Also in malignant ventricular arrhythmias, DL-sotalol was significantly best than six class I drugs in the prevention of new arrhythmias, the therapy being guided by Holter monitoring or electrophysiological studies. We conclude that in the present state of our knowledge, the greatest promise might hold in the area of complex molecules with a diversity of electrophysiological actions, seeming critical the existence of a sympathicolitic effect for an effective protection against sudden death.

Anti-Arrhythmia Agents↗
PubMed1994

[A retrospective study of a population with intermittent atrial fibrillation].

OBJECTIVE: To analyse a population with intermittent atrial fibrillation, comparing the clinical characteristics of patients with the idiopathic form with those with structural pathology. DESIGN: Intermittent atrial fibrillation retrospective study. SETTING: Arrhythmology outpatients clinic of the cardiac department. PATIENTS AND METHODS: Retrospective study of a population of 59 patients with intermittent atrial fibrillation referred to the arrhythmology outpatients clinic of the cardiac department. Forty patients were male and nineteen female with a mean age of 51 +/- 13 years. Idiopathic atrial fibrillation group with 18 patients was compared with the 41 patients group with identifiable pathology. Atrial fibrillation was recognised by 12 lead ECG and 24 hours ambulatory Holter monitoring. Clinical and echocardiographic parameters were analysed. Complications and the efficacy of anti-arrhythmic therapy were referred. MAIN RESULTS: In the studied population, mean age at the identification of atrial fibrillation was lower in the idiopathic group than in the group with identifiable pathology. It was 36 +/- 12 years in the first group and 45.2 +/- 13 in the second. Left atrium dimension was 38.1 +/- 4 mm in the first group and 42.5 +/- 9 mm in the second (p = 0.04). In the group with mitral valvulopathy, left atrium dimension was 45.5 +/- 11 mm, also significantly different from patients with the idiopathic form (p = 0.012). Statistically significative difference between those groups was not found for left ventricular end-diastolic dimension and shortening fraction. Mean follow-up was 3 years with a range between 7 months and 10 years. Effective therapeutic control was obtained in 35 of 59 patients (59.3%). Six were from the idiopathic group (33.3%) and 29 from the group with identifiable pathology (70.7%). Control was not reached or was only partial in 24 patients (40.7%), belonging 66.7% to the first group and 29.3% to the second (p = 0.016). No embolic phenomenon was documented in the idiopathic not anti-coagulated group. Four embolic complications (9.8%) were observed in the group of identified pathology. Three of then were related with mitral valvulopathy and were submitted to effective anti-coagulation therapy. CONCLUSIONS: Patients with idiopathic intermittent atrial fibrillation are younger, with smaller left atrium dimension (mainly in relation to those with mitral valve disease) but are more resistant to anti-arrhythmic therapy. They have a trend to less thromboembolic complications and anti-coagulation is probably not justified.

Adult↗
PubMed1994

[The ventricular dysrhythmia profile in patients with mitral valve pathology].

OBJECTIVE: To study the relation between ventricular arrhythmias and echocardiographic left ventricular data, in patients with mitral valve pathology. DESIGN: Retrospective study, based on Holter department data on ventricular arrhythmias. POPULATION: We studied 128 patients: 36 were male, 92 were female. Their mean age was 52 +/- 11 years. Three groups were outlined: 54 patients had mitral stenosis (ME), 15 patients had mitral disease (MD) and 59 had associated aortic pathology (MA). METHODS: Patients clinical records were reviewed according to an evaluating protocol. In each Holter recorded the number of premature ventricular contractions per hour (PVC/h), as well as the existence of complex ectopic forms (CF) was considered. Echocardiographic left ventricular data used was: diastolic diameter (DD), systolic diameter (DS) and shortening fraction (SF). Treatment was not significantly different between the three groups, when 24 hour monitoring was performed. RESULTS: We found the average number of PVC/h to be 14 +/- 45 in the ME group, 58 +/- 85 in the MD group and 52 +/- 11 in the MA group. There is significant difference between ME and either DM, or MA. In patients with ME significant relations were found between the occurrence of CF a greater DS (p < 0.01) and a lesser SF (p = 0.02). No significance was found for the occurrence of PVC. In patients diagnosed as DM, the occurrence of PVC/h (> or = 10) was related with greater DD (p = 0.01) or DS (p = 0.04), but there was no relation to SF. Finally in the MA group PVC occurrence was strongly related (p < 0.01) with all the echocardiographic values and thinner relations were found towards SF (p = 0.02 for DD, p = 0.03 for DS and p = 0.05 for SF). CONCLUSIONS: Ventricular arrhythmic occurrence is less frequent in ME. However, in the three groups, there is worsening left ventricular arrhythmic frequency in direct relation to greater ventricular dimensions, or compromised systolic function.

Adult↗
PubMed1993

[The circadian profile of ventricular extrasystole].

STUDY OBJECTIVE: to determine the existence of circadian variability (CV) of single ventricular premature beats (VPBs) and study its relationship with the heart rate variation; to compare sub-groups of patients (Pts) with and without antiarrhythmic therapy and with ischemic cardiopathy versus a free structural cardiopathy group. DESIGN: retrospective study. PATIENTS AND METHODS: the CV of VPBs was analyzed by Holter monitoring in 147 Pts, 93 male and 54 female with a mean age of 59 +/- 14.6. Seventy seven Pts were not taking antiarrhythmic drugs while 70 were doing it: Amiodarone 23, Propafenone 30, B-Blockers 9, Quinidine and Disopyramide 7, Flecainide 1. Sixty five Pts had ischemic cardiopathy and 37 were free of any structural abnormality. The selection criteria consisted in: 1--more than 100 VPBs/24h; 2--distribution over more than 12 hours; 3--absence of any hour with more than 35% of the total VPBs in the recording. Data were presented in a percentage form and the results evaluation was made by using single and two-harmonic regression models. MAIN RESULTS: a CV was found to the single VPBs, with minimum values during the nocturnal period and maximum values in the morning, with a significant adjustment to the two-harmonic regression model, defined by the equation y = 4.2 - Q,559 sen (2 pi T/24) - 0.604 cos (2 pi T/24) - 0.417 sen (4 pi T/24) + 0,272 cos (4 pi T/24) (p < 0.001). A strong positive correlation was observed between VPBs and heart rate variability (r = 0.95; p < 0.001). The sub-groups of Pts, whether taking antiarrhythmic drugs or not, also showed a CV with a statistically significant two-harmonic regression pattern, with a major morning increase of VPBs in the antiarrhythmic group. The free structural cardiopathy sub-group displayed a best adjustment to the single harmonic regression model while the ischemic group exhibited a two-harmonic regression pattern. CONCLUSIONS: a significant circadian variability of VPBs with a bi-modality expression was determined. The majority of the analyzed sub-groups showed the same kind of variation. A strong positive correlation with the heart rate variability was observed.

Age Factors↗
PubMed1993

[The catheter ablation of tachyarrhythmias. The experience of the Hospital de Santa Cruz].

BACKGROUND: First results of tachyarrhythmia's direct current (DC) and radiofrequency (RF) catheter ablation in Portugal (St. Cruz Hospital, Carnaxide). POPULATION AND METHODS: Retrospective analysis of the first 20 patients (P) submitted to catheter ablation in our Center: 11 males and 9 females, aging 36 years (SD 14), with drug-refractory symptomatic tachyarrhythmias. DC ablation was used in the first case and RF current in the nineteen subsequent P. RESULTS: Accessory pathway RF ablation: 92% successful rate (12/13 P); AV nodal modification: fast pathway--1 P (DC ablation), slow pathway--3 P (RF ablation) with one case of late clinical recurrence; two successful His bundle ablation (in paroxysmal atrial flutter/fibrillation) one standard right side and other from left ventricle outflow; one successful RF ablation of a verapamil-sensitive ventricular tachycardia. The mean follow-up was 3.5 months (1 to 7 months for RF and 20 months for DC ablation). CONCLUSIONS: Catheter ablation (mainly RF current) is highly effective in tachyarrhythmia's suppression, with 90% global success in our experience without morbidity.

Adolescent↗
PubMed1992

[Relationship between ventricular arrhythmia and clinical and echocardiographic parameters in hypertensive patients].

OBJECTIVE: Evaluation in arterial hypertension (HTA) patients, of the relationship between supraventricular and ventricular arrhythmias, stage of hypertension and echocardiographic parameters. DESIGN: Retrospective study based on the files of ambulatory electrocardiography (Holter). SETTING: Arrhythmology Outpatients Clinic from a Cardiac Department. PATIENTS: Adult patients with arterial hypertension, males and females, who underwent ambulatory electrocardiography (Holter) and echocardiography examinations. MATERIAL AND METHODS: Thirty patients, 15 males and females, 54 +/- 12 years old, were studied. Arterial hypertension was stratified in three stages according with the diastolic value. Symptoms, serum potassium, left ventricular hypertrophy (LVH) on the ECG, and echocardiographic parameters such as left ventricular dimensions, shortening fraction, septal wall and posterior wall thickness and left atrium dimensions were analysed. These parameters were correlated with the arrhythmic pattern concerning the number of premature supraventricular contractions and the number and complexity of premature ventricular contractions (PVC), evaluated by ambulatory electrocardiography (Holter). RESULTS: No relation was found between the arrhythmic pattern, stage of hypertension, symptoms and LVH on the ECG. Septal wall thickness was 14 +/- 3 mm in the group of patients with PVC greater than or equal to 10/hour and 12 +/- 3 mm in the population with PVC less than 10/hour (p less than 0.04). The shortening fraction was 27 +/- 8% in the group of repetitive PVC and 34 +/- 7% in the population without (p less than 0.003). A borderline relation was found between repetitive PVC and left atrium and left ventricular diastolic dimensions. CONCLUSIONS: In a population of arterial hypertension (HTA) who performed ambulatory electrocardiography (Holter), the prevalence of frequent or repetitive PVC was low. A positive correlation between frequent PVC and septal wall thickness and an inverse relation between repetitive PVC and LV shortening fraction, was found. These conclusions are according with the literature, relating the ectopic activity with LVH or deterioration of LV function. No relation was found between arrhythmias and stage of hypertension.

Aged↗
PubMed1991

[Non-invasive evaluation of a population with WPW syndrome].

OBJECTIVE: Evaluation of a WPW Syndrome population by non invasive methods; identification of the sudden death risk; results of treatment and patient selection for Electrophysiologic Studies (EPS). DESIGN: Retrospective study. SETTING: Arrhythmology Outpatients Clinic from a Cardiac Department. PATIENTS: Successive patients older than 12 years with a WPW pattern on the ECG and history of paroxysmal tachycardia followed-up for a period of 46 +/- 29 months. MATERIAL AND METHODS: The clinical, ECG, Holter, stress test and echocardiographic data from 32 patients, were analysed. A study evaluating clinical follow up and the results of treatment was done. RESULTS: The group of patients was very symptomatic. The main complaint was a feeling of tachycardia (84.4%). Orthodromic tachycardia was documented in 7 cases and atrial fibrillation with rapid ventricular rate in five. Intermittent delta wave pattern was found in 21 patients, with 11 cases identified by Holter and 4 by stress test. A predominant left accessory pathway was found (47%), but the anteroseptal location was frequent too (25%). The echocardiogram was not useful in any case. Eighty per cent of the patients became asymptomatic with medical treatment. Beta blockers and amiodarone (the last chance) were the most useful drugs. No mortality was found in the study group. EPS was considered for the 5 patients with paroxysmal atrial fibrillation and the 7 cases resistant to medical treatment. CONCLUSIONS: The difficulty to define the risk of a population with WPW Syndrome by non invasive methods was demonstrated. Eighteen one cases were included in a low risk group, due to the intermittent WPW pattern in the ECG. A high risk group was considered for the 5 patients with atrial fibrillation with fast ventricular rate. The risk was not established in 9 cases. Most of the patients became asymptomatic by medical treatment.

Adolescent↗