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Biomedical subjects

E Zima

Publications and source records attributed to E Zima.

9 recordsLinked to original sources
PubMed2001

[Biventicular pacing in patients with severe heart failure].

According to initial clinical results biventricular pacing seems to be effective in the treatment of patients suffering from drug refractory severe heart failure combined with intraventricular conduction disturbance. Biventricular cardioverter defibrillators and biventricular pacemakers were implanted in patients suffering from drug refractory severe heart failure in 3 and in 2 cases, respectively (follow up > 6 months). NYHA III-IV functional class, low left ventricular ejection fraction (23.2 +/- 5.4%), wide QRS (> 150 ms) with left bundle branch block and lateral dyssynchrony were present in each case. The left ventricle was enlarged in each patient (end-diastolic/end-systolic diameter: 78.6 +/- 9.2/66.2 +/- 8.1 mm). The indications of cardioverter defibrillator implantations were both sustained ventricular tachycardia and ventricular fibrillation, nonsustained ventricular tachycardia combined with syncope in 2 and in 1 case, respectively. The duration of QRS decreased (190 +/- 36 vs. 134 +/- 17 ms, p = 0.012) and wall movement disorder disappeared. At the last follow up every patients were in NYHA II functional class and a decrease in left ventricular diameter could be observed (end-diastolic: 72 +/- 10.4 mm, p = 0.07; end-systolic: 62 +/- 10 mm, p = 0.09). During the follow up period (7.3 +/- 1.7 months) 18 episodes of ventricular arrhythmias could be detected in the same patient. Biventricular pacemakers and cardioverter defibrillators were implanted and applied successfully in the treatment of congestive heart failure for the first time in Hungary. The effect of biventricular pacing on morbidity and mortality, the cost-effectiveness, the exact indication and the combined use with cardioverter defibrillator have yet to be proven in future randomized trials.

Aged↗
PubMed2001

[Biatrial pacing--new possibility in the non-pharmacologic treatment of drug-resistant paroxysmal atrial fibrillation].

Biatrial pacing seems to be a possible non-pharmacological therapeutic choice in the prevention of drug-refractory, paroxysmal atrial fibrillation. Biatrial pacing using standard right atrial and coronary sinus left atrial pacing shows an antiarrhythmic effect, which mechanism is not well understood. Biatrial pacemaker was implanted in three patients suffering from drug refractory, symptomatic paroxysmal atrial fibrillation (lone and nonvalvular in 2 and in one case, respectively). Interatrial conduction disturbance (P > 120 ms) was found in three case. Bradycardia dependent arrhythmia development was not observed. Left atrial and right atrial premature beats dominated in 2 and in one case, respectively. P-wave duration was decreased by biatrial pacing in every patients. Atrial fibrillation has not been detected in two patients 1 day and 4 weeks after pacemaker implantation (follow up period: 9 and 5 months), however antiarrhythmic drugs has been withdrawn. In the number of left atrial premature beats a marked decrease was observed. Neither biatrial nor standard right atrial pacing nor combined medical and atrial pacing antiarrhythmic therapy were proven to be effective. In Hungary we were the first to implant and apply effectively biatrial pacemaker in the prevention of paroxysmal drug-refractory atrial fibrillation. However better identification the responding patients subgroup with atrial fibrillation is needed.

Aged↗
PubMed2001

Shortening the second phase duration of biphasic shocks: effects of class III antiarrhythmic drugs on defibrillation efficacy in humans.

INTRODUCTION: The specific waveform providing optimal defibrillation threshold (DFT) is unknown. We compared the defibrillation efficacy of biphasic pulses with second phases (P2) of 2 and 5 msec in a randomized prospective clinical study. METHODS AND RESULTS: Intraoperative DFTs of 62 patients (age 54 +/- 13 years; ejection fraction 43% +/- 17%; amiodarone 47%, d,l-sotalol 13%) were determined in random order using a binary search protocol. Anodal shocks of 60% tilt first phases (P1) and P2 of 2 msec/5 msec were delivered from two 100-microF capacitors between the right ventricular electrode and the test housing of a Phylax 06/XM device. Mean DFT was significantly lower using the shorter P2 (9.5 +/- 4.5 J vs 11.3 +/- 5.2 J; P < 0.0001). According to subgroup analysis, the effect of changing P2 duration was only influenced by antiarrhythmic treatment. DFT decreased markedly using the shorter P2 in patients treated with amiodarone (10.7 +/- 4.9 J vs 13.4 +/- 5.6 J; P < 0.00001) or d,l-sotalol (6.1 +/- 3.3 J vs 9.1 +/- 4.6 J; P < 0.05). The difference in patients not treated with Class III drugs was found to be insignificant. Chronic amiodarone treatment increased DFT only when the longer P2 was used. CONCLUSION: Biphasic shocks with shorter P2 should be used in patients undergoing Class III antiarrhythmic treatment.

Adult↗
PubMed2001

A new detection algorithm for implantable cardioverter defibrillator.

One of the most important subsystems of implantable cardioverter defibrillator (ICD) is the sensing stage, since it determines the sensitivity and specificity of the device to detect the heart rate and the underlying arrhythmia. This paper aims to investigate a new detection algorithm for ICD, which operates fully automatically. The algorithm ARGUS was implemented as a computer model and tested with intracardiac electrograms recorded (band-pass: 0.05 to 500 Hz; sampling rate: 1-4 kHz) under different rhythm condition like sinus rhythm (n = 18), atrial tachycardia (n = 16), and ventricular tachycardia as well as fibrillation (n = 139) during electrophysiological tests or ICD implantation. The results of the tests were visually inspected on a beat-to-beat basis. In total 31,934 events were classified by the algorithm (18,758 as long intervals (LI) with cycle length > 300 ms; 13,176 as short intervals (SI)). 195 out of the 13,176 SI and 572 out of 18,758 LI were incorrectly classified (SI: 1.48%; LI: 3.05%). In conclusion the new algorithm yield high sensitivity (99.9%) and specificity (97.0%) as known from conventional ICD algorithms but need no manual adjustments.

Algorithms↗
PubMed2001

[Multichamber pacing--a new non-pharmacologic method for the treatment of severe heart failure].

According to initial clinical results biventricular pacing seems to be effective in the treatment of patients suffering from drug refractory severe heart failure combined with intraventricular conduction disturbance. Biventricular cardioverter defibrillators and biventricular pacemakers were implanted in patients suffering from drug refractory severe heart failure in 10 and in 15 cases, respectively. NYHA III-IV functional class, low left ventricular ejection fraction (24.2 +/- 6%), wide QRS (> 150 ms) with left bundle branch block and lateral dyssynchrony were present in each case. The left ventricle was enlarged in each patient (endodiastolic/endsystolic diameter: 78.6 +/- 9.2/68.2 +/- 8.3). The indications of cardioverter defibrillator implantations were both sustained ventricular tachycardia and ventricular fibrillation, nonsustained ventricular tachycardia combined with syncope in 7 and in 3 case, respectively. The duration of QRS decreased (187 +/- 32 vs. 136 +/- 19 ms, p = 0.012) and wall movement disorder disappeared. At the last follow up every patients were in NYHA II functional class and a decrease in left ventricular diameter could be observed (endodiastolic: 70.3 +/- 9.1 mm, p = 0.04; endosystolic: 61.9 +/- 8.8 mm, p = 0.04). During the follow up period (8.8 +/- 5.1 months) 18 episodes of ventricular arrhythmias were detected in the same patient, 2 patients died (1 arrhythmia death, 1 sudden cardiac death). Biventricular pacemakers and cardioverter defibrillators were implanted and applied successfully in the treatment of congestive heart failure for the first time in Hungary.

Cardiac Pacing, Artificial↗
PubMed2000

Endothelin-A-receptor antagonist LU 135.252 inhibits the formation of ventricular arrhythmias caused by intrapericardial infusion of endothelin-1.

Intrapericardial endothelin-1 (ET-1) infusion causes dose-dependent severe ventricular arrhythmias. We examined the effects of the endothelin-A- (ETA) receptor antagonist LU 135.252 (LU) on ET-1-induced arrhythmias on six open-chest mongrel dogs. Ten minutes after an intravenous bolus of LU (5 mg/kg), ET- 1 (33 pmol/kg/min) was given into the pericardial space for 30 min (LU group). Six dogs received ET-1 infusion without LU treatment (control group). Mean arterial blood pressure (MAP), cardiac output, electrocardiograph (ECG), right ventricular endocardial and epicardial (RVEND, RVEP), and left ventricular endocardial and epicardial (LVEND, LVEP) monophasic action potential durations (MAPDs) were recorded. No significant changes were observed in MAP and cardiac output. MAPD90s did not change significantly in the LU group (basic vs ET 20min: RVEP, 186 +/-7 vs 190 +/- 7; LVEP, 189 +/- 8 vs 201 +/- 11; RVEND, 191 +/- 10 vs 192 +/- 9; LVEND, 199 +/- 11 vs 203 +/- 11 ms), while significant MAPD90 prolongation was found in all investigated regions of the control group (ET start vs ET 20 min: LVEP, 174 +/- 3 vs 208 +/- 10*; RVEND, 206 +/- 9 vs 241 +/- 12* ms, *p < 0.05). No early after depolarization (EAD) was observed in the LU group, while EADs occurred in three controls. In the LU group, we have not found any significant arrhythmias except nonsustained ventricular tachycardias (nsVTs) in one animal. In the control group incessant nsVTs were observed in six, sustained VTs (sVTs) in four and ventricular fibrillation (VF) in two instances. Significant ST-elevation was observed in all animals in the LU and control groups (LU: 6.7 +/- 2.1 mV; control: 10.1 +/- 2.0 mV, p = NS). In conclusion, the arrhythmogenic action and the main electrophysiological effects of pericardial ET-1 infusion, MAPD prolongation and EAD formation, are inhibited by LU. However, LU could not prevent the ischemic changes resulting from ET-1 infusion.

Action Potentials↗