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PubMedDate not supplied

Experimental study on the electrophysiological effects of the combination of the antiarrhythmic drugs aprindine and verapamil.

The acute electrophysiological effects of the antiarrhythmic drugs aprindine and verapamil, injected intravenously either alone or in combination, were studied in 14 dogs during invasive electrophysiology. The AH and HV intervals during sinus rhythm were significantly prolonged, especially in the aprindine and the aprindine plus verapamil groups. The cycle lengths of the antegrade and retrograde atrio-ventricular block were most prolonged in the combination group. The effective refractory period and the functional refractory period of the atrial tissue, as well as the functional refractory period of the atrio-ventricular node, the effective refractory period of ventricular tissue and the ventriculo-atrial conduction system were most prolonged when the combination of the agents was given. The effective refractory period of the atrio-ventricular node was prolonged in the groups receiving verapamil and verapamil plus aprindine. There was no significant difference in the serum concentration of each agent given alone or in combination. These results suggest that the efficacy of the combination of verapamil and aprindine may be due to additive or synergistic effects of these antiarrhythmic agents.

Animals↗
PubMed1991

[Lipomatous hypertrophy of the interatrial septum versus lipomatous hypertrophy of the intervenous tubercle].

The lipomatous hypertrophy of the interatrial septum is a clinicopathological entity characterized by an accumulation of fat, not encapsulated but circumscribed in the atrial septum, over the fossa ovalis, and protruding into the right atrium; its thickness exceeding 15 mm. It is clinically associated with atrial electric abnormalities such as disorders of the atrial conduction and supraventricular arrhythmias, difficulty of the venous return and sudden death. In 1669 Lower described at the entrance to the right atrium, between the venae cavae, there is a tubercle formed by an accumulation of fat, covered over with muscular fibres that protrudes into the right atrium, which be called intervenous tubercle. The aim of this work is to find out the normal morphology of the intervenous tubercle and to find out whether or not lipomatous hypertrophy of interatrial septum is related to it in some way, because both coincides anatomically.

Adolescent↗
PubMed1991

[Additional contribution of high amplification electrocardiography in the follow-up of children with muscular dystrophy].

Fifteen children and adolescents with muscular dystrophy underwent investigation by Doppler echocardiography and high amplification electrocardiography to evaluate the quality of left ventricular function. High amplification ECG showed minor intra-atrial conduction defects in 3 cases and abnormal late micro potentials without arrhythmogenic late potentials in 3 other cases. Significant abnormalities were observed in 40% of children examined. Doppler echocardiography showed relative conservation of systolic left ventricular function but a decrease in indices of contractility was observed in 46% of cases, especially in patients with Duchenne muscular dystrophy. Abnormalities of left ventricular distensibility were observed earlier and were more common (53% of cases). A significant decrease in cardiac output was found in 50% of patients, especially among the older and more severely affected children irrespective of the type of muscular dystrophy. These two investigations provide complementary information for the evaluation of left ventricular function of children with muscular dystrophy and they are proposed routinely for the follow-up of these patients.

Adolescent↗
PubMed1991

[The importance of the autonomic nervous system for sinus and atrioventricular node function in patients with sick sinus syndrome].

Autonomous nervous system (ANS) influence on sinus (SN) and atrioventricular (A-V N) nodes is still under investigation, especially in pathological states. We analysed role of ANS for SN and A-VN function in patients with different forms of sick sinus syndrome (SSS). From 310 patients (pts) after electrophysiological examinations before and after pharmacological denervation of the heart we selected 206 pts with SSS (group S) for further investigation. In group S were 124 men and 82 women from 17 years old (mean 46 +/- 16). Coronary heart disease was present in 102 pts (myocardial infarction in 7), mitral valve prolapse in 10, hypertrophic cardiomyopathy in 2. SSS was the only pathological finding in 75 pts. In 92 cases pacemaker was implanted (45%) of whole group S. Only sinus bradycardia was observed in 118 cases, tachycardia-bradycardia syndrome in 34 and sinus arrest or/and sinoatrial block in 53 cases. Electrophysiological examinations were performed using transesophageal stimulation of the left atrium before and after denervation of the heart. Pharmacological denervation of the heart was obtained by propranolol (i.v. 0.2 mg/kg body weight) and than atropine (i.v. 0.04 mg/kg body weight). We analysed sinus cycle length in basic state, after propranolol injection and after full denervation, maximal sinus nodes recovery time, maximal corrected sinus node recovery time, secondary pause, sino-atrial conduction time, Wenckebach point before and after full denervation. The whole group with SSS (group S) was divided: pts with normal (S1) and abnormal (S2) intrinsic properties of SN (104 and 102 pts respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Carotid sinus hypersensitivity. Medium and long-term development in patients treated by ventricular pacing].

The problem of pacing patients with carotid sinus hypersensitivity (CSH) is the choice and criteria of selection of the pacing mode. The authors studied 29 patients with CSH treated by VVI pacing over a period of 10 years. The average follow-up was 34 months (range 6 to 96 months). Three of the 27 patients (11%) who were asymptomatic at the outset continued to have symptoms. The nature of the CSH was well-defined in 25 patients; 19 of the 20 cases of cardio-inhibitory CSH and 4 of the 5 cases of mixed CSH were asymptomatic. These two poor clinical results were analysed: the patient with the cardio-inhibitory CSH (one recurrence in 84 months) had a drop of 40 mmHg in systolic blood pressure which fulfilled criteria of the cardio-inhibitory form of CSH (a drop of 30 to 50 mmHg). The second case was a complete therapeutic failure with 3 recurrent syncopal episodes. The patient had a mixed form of CSH (B.P. drop of 65 mmHg) associated with a "pace maker syndrome" (drop of 50 mmHg in systolic blood pressure at the onset of VVI pacing without any sino carotid massage). The authors conclude that the cases of CSH which, during their investigation, are best corrected by dual-chamber pacing or which are associated with a significant pacemaker effect or present retrograde ventriculo-atrial conduction, should receive dual-chamber pacemakers.

Aged↗
PubMed1989

[New anti-arrhythmia drug. III. Comparative studies of the effects of N-propionylprocainamide, procainamide and N-acetylprocainamide on hemodynamics and cardiac blood flow].

Procainamide (PA) often applied in cases of ventricular arrhythmias causes numerous cardiac and extracardiac undesirable symptoms. Its active metabolite, N-acetylprocainamide (NAPA; Acecainide) is known to affect less noxiously the ventriculo-atrial conduction and the intraventricular++ conduction, and it does not impair contractility of the heart muscle. Many drugs with proven antiarrhythmic activity cannot be used in clinical practice because of disadvantageous effects on the function of the left ventricle and on the coronary blood flow, particularly in patients with the recent myocardial infraction. It seems that another acyl derivative of procainamide with potential antiarrhythmic activity, N-propionylprocainamide (NPPA) may be less harmful than PA, and NAPA. Effects of milimolarly equivalent doses of NPPA, NAPA and PA on the cardiac output and the stroke volume index, as well as on the coronary blood flow were investigated in rabbits by the radioisotope method. The obtained results were subjected to statistical analysis. NPPA was found to display no depressive action on the function of the left ventricle. Moreover, it was found to improve the coronary blood flow in rabbits.

Acecainide↗
PubMed1989

[The diagnostic value of quantitative atrial activation mapping for localization of cardiac accessory pathways].

The diagnostic value of quantitative atrial activation mapping for localization of cardiac accessory pathways (AP) was evaluated in 50 cases with histories of supraventricular tachycardia (SVT). Some possible quantitative criteria are proposed for the differential diagnosis of free wall and septal APs. The diagnostic criteria of septal AP during SVT are 1) Slightly earlier left or right atrium depolarization; 2) time difference between left and right atrial depolarizations (delta A less than or equal to 30 ms; 3) change rate of delta A (delta A%) greater than 50%; 4) delta A index less than 10; and 5) ratio of ventriculo-atrial conduction times between the two atria less than 1.22. The sensitivity of these criteria in the diagnosis of cardiac septal AP is 91.7%, the specificity is 91.5% and the accuracy is 92%.

Adult↗
PubMed1989

[The choice of stimulation mode in patients with cardioinhibitory or mixed carotid sinus hypersensitivity, with or without associated sinus dysfunction].

In this prospective study, we evaluated pacing therapy in 60 consecutive patients affected by syncopes or pre-syncopes and cardioinhibitory or mixed carotid sinus hypersensitivity. We preferred DDD/DVI pacing for the 26 patients who had: 1) the cardioinhibitory form and presence of symptomatic pacemaker effect, or 2) the mixed type I form and presence of symptomatic pacemaker effect, ventriculo-atrial conduction, or orthostatic hypotension, or 3) the mixed type II form, or 4) the presence of severe sinus bradycardia. We preferred VVI mode in the other 34 patients. Syncope or pre-syncope persisted in one patient of the VVI group after the pacemaker implant and in one patient of the DDD/DVI group. Therefore, we obtained the suppression of severe symptoms in 97% of cases (58/60 pts). Yet minor symptoms persisted in 35% and 38% of patients of the two groups, respectively. No patient developed clinical signs of cardiac insufficiency or intolerance to pacing therapy. Besides, in DDD/DVI patients, we performed a single-blind, randomized, cross-over study for a comparison between the DDD/DVI and VVI mode: each patient was paced for two months using each mode and for each period symptoms were analyzed. The VVI period, compared to the DDD/DVI, resulted in a significantly higher incidence of symptoms: syncope 8% vs. 0%; pre-syncope 31% vs 0%; minor symptoms 58% vs. 31%; cardiac failure 19% vs. 0%. So the DDD/DVI mode was preferred by 69% of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[Changes in sinus function at rest and during physical exertion after permanent atrial electrostimulation in patients with sick sinus syndrome].

We studied the unnatural history of sinus node function in severe sick sinus syndrome treated with AAI or DDD pacemakers. In 19 patients (10 m; 9 f; mean age +/- 1 SD 69 +/- 7 years) we executed serial bicycle exercise tests and electrophysiological studies before, 7 days and 3 months after pacemaker implant. Sinus heart rate at maximum effort was: 118 +/- 23 beats/min and 117 +/- 23 beats/min (two different evaluations) before pacemaker implant, 125 +/- 21 beats/min after 7 days (p less than 0.05) and 133 +/- 20 beats/min after 3 months (p less than 0.001) with an average increment of 12.7%. A positive correlation (y = 50.4 + 0.7 X beats/min; p less than 0.001) between the first basal test and the third month one was found. In analogy exercise test lasted 8.7 +/- 3, 8.6 +/- 2.8, 9.5 +/- 2.5, 9.7 +/- 2.5 minutes respectively, with an average increment of 11.5% between the first basal test and the third month one. Sinus heart rate at maximum effort in 14 age matched normal subjects was 138 +/- 15 beats/min. The difference with sick sinus syndrome patients was statistical (p less than 0.05) when compared with the basal test but not with 3rd month test. Parameters determined during electrophysiological studies were: spontaneous heart rate, corrected sinus node recovery time, sino-atrial conduction time evaluated before and after autonomic blockade (propranolol 0.2 mg/kg i.v. plus atropine 0.04 mg/kg i.v.). All these parameters, excepting basal corrected sinus node recovery time, improved significantly after pacemaker implant.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

[Differential therapeutic problems in sinus node syndrome--drug or electrical therapy?].

121 hospitalised patients with electrophysiologically ascertained sick sinus syndrome were ambulatorily observed for two and a half years. The knowledge of the electrophysiological parameters allowed in every case an exact estimation of the degree of severity. Patients with preponderantly isolated disturbance of the sino-atrial node automatism, the sino-atrial conduction and the nervous regulation (patients with carotid sinus syndrome) as well as the majority of patients with bradycardia-tachycardia-syndrome were conservatively treated. Patients with high-degree combined disturbances of the sinus node partial functions were electrically treated. Every cardiac syncope in the medicamentously treated sick sinus node syndrome is the absolute indication for a pacemaker implantation. The further observation in the outpatient department showed that in many patients with symptomatic sick sinus node syndrome an attempt of conservative treatment is justified.

Anti-Arrhythmia Agents↗
PubMed1985

[Diagnostic value of clinical electrocardiography indices for recognizing myocardial infarct of the right and left ventricles].

The sensitivity, specificity, predictive value and informative value of clinical and electrocardiographic indices were assessed in patients with verified diagnoses of concomitant (17) and isolated left ventricular (23) myocardial infarction. The most informative and specific signs in terms of involvement in the right ventricular process were: pulse and respiration rate, posterir-low site of left ventricular lesion, disorder of the atrioventricular conduction, atrial fibrillation, reversible ventricular fibrillation, change of the Marcus index and amplitude of the P wave.

Electrocardiography↗
PubMed1978

[Recording the electrogram of the sinus node. Effects of the injection of tetrodotoxin into the artery of the sinus].

The cells of the SA node (SAN) are very resistant to the action of tetrodotoxine (TTX), a drug which. paradoxically, blocks depolarisation of the outer myocardial cells. Injection of TTX into the artery of the SAN brings about asystole; bur regular electrical activity, consisting of a slow wave of 200 to 300 ms duration, can still be picked up by an electrode placed on the SAN. This electrical activity, which can only be picked up over the SAN, and is resistant to TTX but blocked by acetylcholine, is interpretated as being the electrogram of the SAN. After the artery has been washed out by normal saline, the effect of TTX becomes progressively less; under these conditions, all degrees of sino-atrial block can be observed. Arising from a study of the phenomena of capture of the SA and AV nodes, of the effect of artrial stimulation, and of the time relationships between the various electrical events recorded, some hypotheses of the electrophysiology of the SAN and the sino-atrial conduction are put forward.

Acetylcholine↗
PubMed1979

Sinus node disease.

Sinus node dysfunction may be clinically asymptomatic or may lead to serious arrhythmias and sudden death. Symptomatology relates to the resulting brady- or tachyarrhythmias. Clinical and electrocardiographic assessements fail to identify the cause in many patients. Ambulatory electrocardiography establishes the diagnosis in a greater percentage of patients and permits the direct correlation of symptoms with rhythm disturbances. Functional electrophysiologic testing which examines the sinus node response to constant atrial pacing and premature atrial stimulation may be performed for further evaluation of these patients. Sensitivity and specificity of sinus node recovery times (SNRT) and sino- atrial conduction time (SACT) derived by functional testing vary markedly in different reports. This variation may relate to differences in patient population, limitations of testing procedures, and the uncertainties as to the normal limits of SNRT and SACT. As a result, the full value of these tests in diagnosis and in furthering our understanding of sinus node disease remains to be established. At present, permanent pacing remains the definitive treatment in symptomatic patients.

Animals↗
PubMed1984

[Arrhythmia in relation to acute alcoholic intoxication in the absence of obvious cardiopathy].

Following acute intoxication with alcohol, 8 patients developed 16 episodes of arrhythmia, including 15 supraventricular tachycardias and one torsade de pointe. Seven of the 8 patients were chronically abusing of alcoholic drinks. None of the patients had clinically obvious cardiac pathology nor echocardiographic evidence of myocardiopathy. In 7 of them, however, baseline electrocardiograms disclosed disorders of intra-atrial conduction. The role of the different factors which might determine the occurrence of arrhythmia (notably alcohol, the autonomic nervous system, associated metabolic abnormalities and absorption of medicines) is discussed.

Adult↗
PubMed1984

The prevention of pacemaker mediated tachycardias in double-chamber pacing.

In 32 consecutive patients selected for physiological pacing assessment of ventriculo-atrial conduction (VAC) was performed, with incremental pacing and ventricular extrastimulation. This is easily done intraoperatively; VA conduction was present in 13 patients. When sinus node disease accompanied antegrade block retrograde conduction never occurred. The mean VA time was 241 +/- 42 ms (Mean +/- standard deviation). One patient developed pacemaker mediated tachycardia while negative findings were present; it was induced by coupled ventricular premature beats. Two patients of the group with VAC had to be reprogrammed in DVI because of disabling symptoms. Pacemaker tachycardia usually develops within the first hours after implantation. The mechanisms and the ways to prevent the tachycardia are discussed.

Arrhythmias, Cardiac↗
PubMed1978

[The Senning operation for correction of transposition of the great arteries (author's transl)].

The reported incidence of the main complications related to the Mustard operation for correction of transposition of the great arteries seems to be quite high: more than half patients develop arrhythmias and about one third develop venous (pulmonary or sistemic) obstructions. For these reasons we have reconsidered the type I (1959) Senning operation. Ten children below two years of age (body weight ranging from 3.9 to 12 Kg) have been operated on with this technique at our Institution. Nine were D-TGA and one L-TGA. One patient had a small VSD and three had mild pulmonary outflow stenosis (p less than 30 mmHg). All patients survived operation and none suffered from complications. At the time of the discharge from the Hospital all were in sinus rhythm. Late evaluation (24 hours EKG, cardiac catheterization, etc.) is in course. We believe that the Senning operation is easier to perform than the Mustard operation because of its more standardized technique which respects the internal geometry of the heart. Additional advantages are: 1) the intra-atrial conducting pathways are less likely to be damaged; 2) there is a minimal or no need for artificial tissues.

Child, Preschool↗
PubMedDate not supplied

Sinoatrial disorders, the "sick sinus" syndrome. Experience with implanted cardiac pacemakers.

The long term results of permanent pacemaker implantation in patients with disorders of the sinoatrial node and atrial conduction pathways were studied. In a consecutive series of 300 patients treated by pacemaker implantation, 68 ((22.3%) had sinoatrial disorders. Mean age of the group was 54 years (33-82 years); 37 were male, 31 female. Diagnosis was confirmed by serial electrocardiography with overdrive suppression of sinoatrial node function as indicated. Twenty-two patients presented with sinus bradycardia alone (Type I disorder) and 46 with bradycardia-tachycardia syndrome (Type II disorder) were completely controlled. of the 46 Type II patients, in 30 (65.2%) tachyarrhythmias were controlled by pacing alone and in 14 (30.4%) by pacing and antiarrhythmic drug therapy. Congestive cardiac failure was relieved in 80% and anginal pain in 70% of patients with rate control alone. Systemic embolisation did not recur after pacemaker implantation. The average duration of pacemaker therapy was 52 months (12-96 months). In this series, long term ventricular demand pacing proved beneficial in both types of sinoatrial disorders.

Adult↗
PubMed1982

[Vectorcardiographic analysis of atrial activation in isolated mitral valve prolapse. Atrial vectorcardiography in prolapsed mitral valve].

The purpose of our work is to study atrial depolarization in primary mitral prolapse (MVP), since, as far as we know, such a study has never been performed. Thirty patients with MVP were studied: 23 females, aged 37,3 +/- 15,5 years and 7 males, aged 45.1 +/- 18.1 years. MVP was diagnosed by M-mode echocardiography. Atrial depolarization was analysed on photographically recorded Frank's vectorcardiograms. On PsE loops, magnitude and direction of maximum planar vector (VMax) in the frontal (F) and left sagittal (LS) planes, magnitude and direction of anterior (HV1) and posterior (HV2) vectors in the horizontal (H) plane, HV1 to HV2 amplitude ratio and total atrial activation time (T) were measured. This last value (T), measured on vectorcardiographic records, was confirmed by high-speed (200 mm/sec) electrocardiograms. These data were compared, by mean of Student's test, with those measured on records obtained from a similar group of normals. The following statistically significant (P less than 0.05) differences were detected: decreased amplitude of VMax in F (0.11 +/- 0.03 vs. 0.080 +/- 0.03) and LS (0.11 +/- 0.03 vs. 0.085 +/- 0.03), backward shift of HV2 (+65 degrees +/- 39 degrees vs. + 11 degrees +/- 35 degrees) and decreased T (98 +/- 25 vs. 85 +/- 17). The decrease of total atrial activation time, about 13% less than in normals, is the most interesting finding of our research. Such an alteration of atrial depolarization can be explained by inter- and/or intra-atrial conduction disturbance, on anatomical or functional base. Therefore, our findings are consistent either with the hypothesis that MVP is secondary to widespread pathological changes or with the one that MVP is a consequence of neurovegetative imbalance.

Adolescent↗