Search PubMed⌕ Search

Biomedical subjects

B D Gonska

Publications and source records attributed to B D Gonska.

At least 55 records · Page 3Linked to original sources
PubMed1991

Radiofrequency catheter ablation in recurrent ventricular tachycardia.

Catheter ablation by radiofrequency energy was carried out in 10 patients with one type of recurrent monomorphic sustained ventricular tachycardia resistant to medical antiarrhythmic management. Electrophysiological studies before ablation included activation and pace-mapping. In all patients, the origin of the tachycardia was localized in the left ventricle: in the septum in six, at the posterolateral wall in three and anterobasal in one. The earliest onset of endocardial activation preceding the QRS complex during ventricular tachycardia ranged between -45 and -90 ms. Transcatheter ablation was performed with a bipolar or quadripolar catheter using a radiofrequency generator (HAT 100, Osypka). No complications occurred during the ablation procedure. Thereafter, in all patients, the clinical tachycardia was no longer inducible by programmed stimulation. During a follow-up period of 22 to 32 months including eight patients, the tachycardia recurred in two; one of these patients subsequently died suddenly. A third patient had one episode of a new type of sustained ventricular tachycardia some hours after catheter ablation. In the remaining patients, there was no recurrence of symptomatic tachycardia under maintenance of the antiarrhythmic management which, prior to ablation had been ineffective. Thus, our preliminary results suggest that radiofrequency catheter ablation might be beneficial for these high risk patients.

Cardiac Pacing, Artificial↗
PubMed1991

Prevalence of late ventricular potentials in hypertensive patients.

Late ventricular potentials detected by signal averaging are used for predicting ventricular arrhythmias and sudden cardiac death in patients with coronary artery disease. We studied the prevalence of signal-averaged late ventricular potentials in 37 male patients (mean age of 56 years) with angiographically normal coronary arteries. Seventeen patients were hypertensive (group A) and 20 patients were normotensive (group B). In group A, 5 of 17 patients (29%) had late ventricular potentials. In group B, only 1 of 20 patients (5%) had late potentials (p less than 0.05). Late ventricular potentials detected by signal averaging are more common in hypertensive patients than in healthy controls. Whether late ventricular potentials can be used to predict malignant ventricular arrhythmias or sudden cardiac death in hypertensive patients will have to be investigated in further studies.

Action Potentials↗
PubMed1991

[Prevalence of late potentials in high frequency signal-averaged electrocardiography and arrhythmias in long-term ECG in healthy probands].

In a prospective study 79 symptom-free persons (41 females; 38 males) with an age range of 22-69 (mean 44) years were investigated by 48-h continuous ambulatory electrocardiography and by the signal-averaging ECG according to Simson's technique after having normal findings with echocardiography, standard ECG at rest and exercise stress test. Late potentials were defined according to Denes criteria (40 Hz highpass-filter); at least two out of the following three criteria had to be fulfilled for a correct positive finding: 1) QRS duration (QRSdur) greater than 120 ms; 2) root mean square of the last 40 ms (RMS 40) less than 20 microV; 3) mean duration of terminal low-amplitude signals (LAdur) greater than 39 ms. With long-term ECG 25% of the test subjects had no ventricular extrasystoles (VES), 28% had uniform VES, 33% multiform VES, 10% couplets, and 4% short runs of ventricular tachycardia during 48-hour recordings. Only 19% of them showed more than 48 VES/48 h. Individuals of advanced age demonstrated arrhythmias of higher Lown classes, as well as more frequent VES. By applying the signal-averaging technique 12.6% of the apparently healthy individuals showed late potentials, but none had LAdur greater than 45 ms. Individuals of higher age had not more late potentials than the younger ones. However, individuals with incomplete right bundle branch block pattern (n = 6) demonstrated with 50% significantly more often later potentials in comparison to 9.6% of those without this pattern (n = 73) (P less than 0.05). There was no correlation between late potentials and spontaneous arrhythmias, neither with regard to Lown classes, nor with regard to the frequency of VES. In conclusion, late potentials may occur in some individuals without apparent cardiovascular disease; they are unrelated to age as well as to spontaneous ventricular arrhythmias in normals.

Adult↗
PubMed1991

[Effect of thrombolytic therapy in acute myocardial infarct on incidence of ventricular late potentials].

The aim of thrombolytic therapy for acute myocardial infarction is reperfusion of the infarction-related vessel. Ventricular late potentials detected by signal averaging have been demonstrated to be related to slow and inhomogeneous conduction within damaged cardiac tissue. In 75 patients with first myocardial infarction the effect of thrombolysis on ventricular late potentials was studied. Reperfusion of the infarction-related vessel could be demonstrated by coronary angiography in 53 (71%) patients. In 22 patients (29%) there was no reperfusion. In the 53 patients with successful thrombolysis the incidence of late potentials was significantly lower (9%) than in the 22 patients without reperfusion (50%). The lower incidence of late potentials may demonstrate improved ventricular electrical stability.

Adult↗
PubMed1990

[Delayed-release verapamil hydrochloride in chronic atrial fibrillation. Reducing the heart rate].

In an open clinical trial, the therapeutic effect of sustained-release verapamil hydrochloride was investigated in 40 patients with chronic atrial fibrillation. As required, the daily dose was increased from 240 mg to 480 mg. A clinically relevant, statistically significant decrease in the heart rate was observed in almost all the patients. Since only four patients experienced mild side effects, with no major clinical significance, the preparation has a positive benefit/risk ratio for the indication investigated.

Aged↗
PubMed1990

[Ventricular arrhythmia and late potentials in patients with hypertrophic cardiomyopathy].

Holter monitoring (48 h) and registration of signal-averaged late potentials (method of Simson, high pass filter 40 Hz) were performed in outpatiens with hypertrophic cardiomyopathy. A prevalence of spontaneous ventricular arrhythmias could be determined in 51 patients; the results of 45 patients not taking antiarrhythmic drugs are presented here. 96% of these showed ventricular premature beats, 76% had multiform extrasystoles, 27% showed pairs of ectopic beats and 20% had runs of ventricular tachycardia (more than 3 QRS complexes). Absolute counts of premature beats were low in most patients, but important interindividual differences could be observed: M = 34 extrasystoles/24 h (0-4943). Ventricular tachycardias were of short duration (maximum 11 QRS) with heart rate ranging from 120 to 200/min. All patients were asymptomatic during tachycardia. Signal-averaged late potentials could be registered in 30 patients, 28 of them without antiarrhythmic drug therapy. Mean QRS duration (QRSdur) was 108 +/- 12 ms, mean duration of low amplitude signals (less than 40 microV) in the terminal portion of the QRS (LAdur) was 27 +/- 13 ms, and mean amplitude of the last 40 ms of the filtered QRS (LAamp) was 65 +/- 43 microV. A patient was considered to show late potentials if two of the following criteria were present: QRSdur greater than 120 ms, LAdur greater than or equal to 40 ms, LAamp less than 20 microV. This was found in four patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Value of various concepts in long-term electrocardiography].

With the introduction of long-term ECG by N. Holter more than 25 years ago a more sensitive detection of spontaneous arrhythmias and ST-changes became possible compared with the standard ECG at rest. Unfortunately, visual high-speed analysis of the tapes caused remarkable loss of stored informations due to the failure of rapid identification. Full disclosure of the ECG, therefore, is a valuable supplement to long-term ECG. As an isolated method, however, it cannot be recommended since the significantly reduced amplitude and paper speed of full disclosure likewise is responsible for a remarkable loss of informations. Only computer-aided analysis of the ECG provides more complete information and at the same time more quantitative data. Analysis of the accuracy of different computer-based systems showed, however, that a sensitivity as well as a positive predictive accuracy of 100% remains the exception to the rule. Moreover, the spectrum of cardiac arrhythmias and ST-changes identifiable by automatic analysis is small. For these reasons, interaction of the user is mandatory--in order to validate computer results as well as to detect ECG abnormalities unidentifiable by computer. The first is possible only to a limited degree with discontinuous ECG recording by event recorders, the last remains impossible. Thus, the promising concept of real-time cardiac monitors should be considered investigational or experimental at this time.

Arrhythmias, Cardiac↗
PubMed1988

[Monitoring of pacemaker patients by long-term ECG].

Long-term-ECG is an essential method for detecting transitory pacemaker-dysfunctions. Control of antitachycardia-pacemakers is possible as well as VVI-pacemakers and with restrictions DVI-, VDD- and DDD-pacers. Special pacemaker-control-modules increase the sensitivity for the recognition of dysfunctions. Regular check-ups are an important part of guiding the pacemaker-patient.

Arrhythmias, Cardiac↗
PubMed1988

Endocardial late potentials recorded during sinus rhythm in man: incidence in different cardiac disease states.

In a prospective study, 100 patients with various cardiac diseases not selected on the basis of previous ventricular arrhythmias underwent left ventricular endocardial mapping. With 10 different positions of the quadripolar catheter per patient, 90 of the 100 patients showed late potentials. These findings were documented in 50 of 52 patients with coronary heart disease compared to 26 of 34 patients with dilative cardiomyopathy (p less than 0.025). Late potentials in diastole were the most frequent type of abnormal electrogram, found in 82 patients. Fractionated electrograms were documented in 43 patients. They were seen in 27 (52%) coronary patients more often than in 8 (24%) patients with dilative cardiomyopathy (p less than 0.025). Onset of fractionated electrograms in coronary patients was somewhat later (301 +/- 177 ms after the QRS) than in the cardiomyopathy group (263 +/- 141 ms). The duration was longer (189 +/- 114 ms) in the former group than in the latter (148 +/- 87 ms). Thus, endocardial late potentials are not uncommon in patients with various cardiac diseases. The more frequent occurrence in coronary heart disease and the higher frequency of fractionated electrograms may indicate a more inhomogeneous, patchy type of fibrosis in the ischemically diseased myocardium.

Adult↗
PubMed1988

Occurrence and clinical significance of endocardial late potentials and fractionations in idiopathic dilated cardiomyopathy.

In order to assess the occurrence and clinical significance of abnormal electrograms in idiopathic dilated cardiomyopathy, endocardial electrode mapping during sinus rhythm and programmed ventricular stimulation were performed in 52 patients with or without clinical ventricular tachycardia. Abnormal endocardial electrograms were recorded in 77% of the patients and were diffusely distributed over the entire left ventricular endocardium. No relation could be established between the occurrence of late potentials or fractionations and clinical or induced arrhythmias. Endomyocardial biopsy samples were taken from 20 patients and showed that reduced myofibril volume fraction was related to the occurrence of abnormal endocardial electrograms. Neither induced arrhythmias nor the presence of late potentials or fractionations identified patients who died of sudden cardiac death during the mean (SD) follow up of 33 (11) months. Thus abnormal endocardial electrograms recorded during sinus rhythm in idiopathic dilated cardiomyopathy may only be interpreted as being a sign of damage to the myocardial cells.

Action Potentials↗
PubMed1987

Programmed ventricular stimulation in coronary artery disease and dilated cardiomyopathy: influence of the underlying heart disease on the results of electrophysiologic testing.

In order to evaluate the clinical and prognostic significance of programmed ventricular stimulation (PVS), 100 patients were investigated. Twenty-four of 51 patients with coronary artery disease and 22 out of 49 with dilated cardiomyopathy had clinical ventricular tachycardia (VT). The study protocol included 24-h Holter ECG, cardiac catheterization and angiography, and PVS employing 1 and 2 premature extrastimuli and incremental pacing. In patients with coronary artery disease, VT was induced in 67% with prior VT and in 18% without such episodes (p less than 0.01). In dilated cardiomyopathy, however, patients with and without clinical VT did not differ with regard to VT inducibility (18% vs. 15%, NS). The inducibility of monomorphic sustained VT--most frequently induced in VT patients--was significantly higher in patients with coronary artery disease (p less than 0.05). Polymorphic nonsustained VT (in both coronary artery disease and dilated cardiomyopathy) was only initiated in patients without clinical VT. In patients with coronary artery disease, left ventricular ejection fraction could be correlated to clinical arrhythmia (p less than 0.001), while induced VT could only be correlated to depressed left ventricular function in patients with left ventricular aneurysm. Neither clinical nor induced VT could be correlated to left ventricular ejection fraction in patients with dilated cardiomyopathy. During a mean follow-up of 21 months, 7 patients died from sudden cardiac death. Six of them had clinical VT, but in only 1 patient with coronary artery disease was VT initiated. There was no apparent difference in the antiarrhythmic therapy of the patients with sudden death with respect to the surviving population. In conclusion, the response to PVS with the stimulation protocol applied is different in patients with coronary artery disease and dilated cardiomyopathy. The prognostic significance of the results obtained from PVS remains uncertain.

Adult↗
PubMed1987

[Spontaneous and stimulus-induced arrhythmia behavior in dilated cardiomyopathy].

To assess the incidence and significance of spontaneous and induced ventricular arrhythmias in idiopathic dilated cardiomyopathy, 24 h ambulatory electrocardiographic monitoring and programmed ventricular stimulation were performed in 52 patients. The mean left ventricular ejection fraction was 38 +/- 13%. Ventricular arrhythmias were present in 94%: 56% had non-sustained ventricular tachycardia with 3-20 consecutive VPCs and 17% ventricular pairs. In 56% of patients, more than 10(3) single VPCs/24 h were seen. Repetitive ventricular response was induced by programmed stimulation in 28 patients (54%): in 39%, 2-4 VPCs and in 15%, greater than or equal to 5 VPCs. In three patients (6%), sustained ventricular tachycardia (greater than or equal to 30 s) was initiated, which was of a monomorphic configuration in two of them. The incidence of induced ventricular arrhythmias could neither be correlated with the Lown grade of spontaneous arrhythmias nor with the total number of single VPCs/24 h. The inducibility of sustained ventricular tachycardia, however, was only seen in patients with arrhythmias of Lown grade IVb. No clear correlation could be determined between the impairment of left ventricular function and spontaneous or induced arrhythmias. During the 9-48 (median 34) months' follow-up, nine patients (17%) died, three of them died suddenly and five in congestive heart failure. All sudden cardiac death victims and three out of the five who died of congestive heart failure had non-sustained ventricular tachycardia during 24 h ambulatory electrocardiographic monitoring, but no higher incidence of single VPCs than the survivors. All patients who died had a significantly reduced left ventricular ejection fraction as compared to those who survived. In none of the patients who died were there more than three consecutive VPCs induced by programmed ventricular stimulation.

Adult↗
PubMed1986

[Amiodarone therapy--behavior of serum and fatty tissue concentrations].

Thirty-eight patients with refractory supraventricular and ventricular tachyarrhythmias were administered a mean oral dosage of 400 mg amiodarone daily (200-600 mg). A high-pressure liquid chromatography method was used to measure serum concentrations of amiodarone and its metabolite desethylamiodarone after one week, one month, three months, and then at 6-month intervals. In 24 patients subcutaneous fatty tissue concentrations were also measured. The mean follow-up was 9 months (4 days to 29 months). A linear correlation was found between amiodarone and its metabolite in serum (r = 0.56, p less than 0.001) as well as in subcutaneous fatty tissue (r = 0.67, p less than 0.001). While serum concentrations were dose dependent, tissue concentrations accumulated during chronic therapy (p less than 0.01, both). Clinical efficacy was achieved in 84% of the patients. No statistically significant difference was found between responders and non-responders as regards serum and subcutaneous fatty tissue concentrations. Side effects of amiodarone occurred in 63%. The incidence of adverse effects was related to significantly higher serum and subcutaneous fatty tissue concentrations of amiodarone and its metabolite (p less than 0.001, both). Thus, although the determination of serum and subcutaneous fatty tissue concentrations does not seem to be helpful for assessing clinical efficacy of this antiarrhythmic drug, these values may predict the occurrence of adverse effects.

Adipose Tissue↗
PubMed1985

[Diuretic monotherapy in heart failure. Comparison of piretanide and hydrochlorothiazide-triamterene].

The effects of piretanide and a hydrochlorothiazide (HCT)-triamterene combination were compared in an open, controlled, randomised study on two groups of 15 patients, aged 42-74 years, with congestive heart failure (NYHA II-III). Weight loss was significant in both groups (P less than 0.05). At the end of the 14 day investigation ten patients from the piretanide group but only four patients from the HCT-triamterene group were fully recompensated. The left ventricular end-systolic and end-diastolic diameters were significantly less under piretanide (P less than 0.05 and P less than 0.01, respectively) than under HCT-triamterene. The shortening fraction and the circumferential velocity of shortening under piretanide increased by 25% over the initial value (P less than 0.001) whereas HCT-triamterene produced no change. A small but statistically significant (P less than 0.05) fall in serum potassium as well as a rise in urinary potassium, sodium and chloride concentration occurred with piretanide.

Adult↗
PubMed1985

[Ventricular arrhythmias in left coronary main branch stensosis].

It is far from clear whether ischemia plays a major role in the genesis of ventricular arrhythmias in patients with chronic coronary heart disease. Since patients with left main coronary artery disease suffer from transient or even chronic ischemia including significant parts of the left ventricular muscle mass, it seems worthwhile looking for spontaneous arrhythmias in this particular clinical setting. Therefore we studied 56 patients (53 males, 3 females) with documented left main coronary artery disease (20 patients (35%) with 30-50% luminal narrowing, 36 patients (65%) with greater than or equal to 50% stenosis) using 24-hour continuous ambulatory electrocardiography. Only 5 patients were without ectopic activity. 32 patients (57%) showed ventricular extrasystoles (VES) of uniform or multiform configuration according to Lown class I-III, whereas 19 patients (34%) demonstrated consecutive VES equivalent to Lown class IV. In ten of the latter short runs of ventricular tachycardia (Lown IVb) were the maximal finding. No relation could be assessed between spontaneous ventricular arrhythmias and the extent of coronary artery disease, neither with regard to the degree of narrowing of the left main coronary artery, nor with regard to the additional coronary involvement in terms of 1-, 2- or 3-vessel disease. In contrast, there was a significant relationship between impaired left ventricular function in terms of biplane left ventricular ejection fraction and frequent VES (chi 2 = 11.272; p less than 0.01) as well as complex, namely consecutive forms (chi 2 = 9.548; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Electrophysiologic findings in patients with Kearns-Sayre syndrome--report on 2 cases].

The Kearns-Sayre syndrome is identified by the triad of progressive external ophthalmoplegia, atypical pigmentary retinopathy, and conduction disturbances. In addition, clinical manifestations may include mental retardation, sensorineural deafness, cerebellar ataxia, and facial and peripheral muscle weakness. Morphologic alterations in skeletal muscle may be characterized by ragged-red fibers. Two patients with Kearns-Sayre syndrome underwent electrophysiological examination. The first patient had a first and second degree AV block (Mobitz type II), right bundle branch block, and left axis deviation. The His-bundle electrogram showed a prolonged HV interval as a hint at an intraventricular conduction delay. The signal-averaging technique and endocardial mapping revealed ventricular after-depolarizations. The second patient had an unsuspicious ECG, recurrent atrial tachycardias, normal atrial and ventricular conduction, and after-depolarizations in endocardial mapping. Two months later he showed a second degree AV block combined with clinical symptoms. Pacemakers were implanted in both patients. Beside disturbances of the conduction system in both patients signs of electrical instability of the myocardium were found. In this way the Kearns-Sayre syndrome may be seen as a form of cardiomyopathy.

Adult↗