Biomedical subjects

B Cauchemez

Publications and source records attributed to B Cauchemez.

At least 37 records · Page 2Linked to original sources

PubMed1995

Characteristics of the ventricular insertion sites of accessory pathways with anterograde decremental conduction properties.

BACKGROUND: Accessory pathways (APs) with anterograde decremental conduction properties referred to as Mahaim fibers have recently been recognized as originating from the right lateral atrium. Little information is available about their distal insertion. The purpose of this study was to determine the different kinds of APs involved and the characteristics of their distal insertion site. METHODS AND RESULTS: Twenty-one patients (mean age, 28 +/- 13 years) with reciprocating tachycardia or atrial fibrillation were studied. Right-sided atrial and/or ventricular endocardial mapping during tachycardia identified different types of APs. (1) Seventeen patients had long APs originating from the right lateral atrium and coursing several centimeters to the right ventricle. In 10 patients, the AP terminated in or close to the right bundle-branch system (atriofascicular AP) and in 7, the AP terminated in the anterior right ventricle (atrioventricular AP). Patients with atriofascicular APs had narrower QRS complexes (133 +/- 10 versus 165 +/- 26 milliseconds, P = .02) and narrower initial r wave in leads V2 through V4 during maximal preexcitation than patients with atrioventricular APs. In addition, they had earlier His-bundle and right bundle-branch retrograde activation, ie, shorter V-His (16 +/- 5 versus 37 +/- 9 milliseconds, P < .01) and V-right bundle intervals (3 +/- 5 versus 25 +/- 6 milliseconds, P < .01). In 6 patients, minimal preexcitation not readily apparent was present in sinus rhythm despite the appearance of a narrow QRS complex. A wide distal insertion site of 0.5 to 2 cm in diameter consistent with arborization of the AP was found in 10 patients. The distal application of radiofrequency current produced a change in the preexcitation pattern in 4 patients and ablated the AP in 2 patients. In the other patients, radiofrequency current was applied more proximally and successfully ablated the AP bundle (n = 9) or AP proximal insertion (n = 6). No recurrence was observed during a follow-up period of 12 +/- 10 months. (2) Four patients had short paratricuspid atrioventricular APs; in one, the decremental conduction property was acquired as demonstrated by two electrophysiological studies performed 7 years apart. Radiofrequency ablation was successfully accomplished in all 4 patients at the tricuspid annulus. CONCLUSIONS: Different types of APs account for tachycardias previously called Mahaim fibers. Long and short atrioventricular APs are observed in 81% and 19%, respectively. Long APs often have a distal arborization and may have either a fascicular or ventricular insertion. Radiofrequency current is more efficient when applied to the AP bundle or AP proximal insertion rather than to the distal insertion in patients with long APs.

Adult↗

PubMed1995

Spontaneous sequences of onset of torsade de pointes in patients with acquired prolonged repolarization: quantitative analysis of Holter recordings.

OBJECTIVES: This study investigated the cycle length changes preceding the spontaneous onset of torsade de pointes in patients with acquired prolonged ventricular repolarization. BACKGROUND: Torsade de pointes is a polymorphic ventricular tachycardia generally associated with prolonged ventricular repolarization. Because torsade de pointes is not inducible by programmed electrical stimulation, quantitative analysis of Holter recordings of spontaneous episodes may clarify the mechanisms favoring the onset of torsade de pointes in actual clinical conditions. METHODS: The digitized Holter recordings of 12 patients were analyzed by a computerized Holter system (ATREC). All arrhythmias were grouped according to three classes: 1) isolated premature ventricular beats (n = 47,147, mean/patient [+/- SD] 3,929 +/- 11,571); 2) salvos of 2 to 4 consecutive beats (n = 2,003, mean/patient 167 +/- 359); 3) torsade de pointes > or = 5 beats (n = 105, mean/patient 9 +/- 11). For each patient and class of arrhythmias, six variables were computed from the 10 min and the 10 cycles preceding the event onset. RESULTS: A significant heart rate increase in the last minute (p < 0.01) and typical oscillatory short-long-short cycle length sequences preceded the onset of arrhythmias, with greater oscillation preceding torsade de pointes than salvos and premature ventricular beats. The cycle lengths preceding the onset were highly correlated with the class of arrhythmias (r = 0.65, p < 0.005) and allowed the correct classification of 69% of events by discriminant analysis (p < 0.0001). A significant negative correlation was observed between the duration of torsade de pointes and the mean length of the initial cycles (r = -0.62, p < 0.001), indicating that longer torsade de pointes had a faster rate than that at onset. CONCLUSIONS: In patients with acquired prolonged repolarization, the spontaneous onset of ventricular arrhythmias was preceded by an increasing heart rate in the last minute and escalating oscillatory "short-long-short" cycle length patterns, with greater oscillations preceding torsade de pointes than salvos and isolated ventricular beats. These findings suggest that adrenergic- and pause-dependent mechanisms (possibly inducing afterdepolarizations and triggered activity) may have a synergetic role in the genesis of complex ventricular arrhythmias associated with delayed ventricular repolarization.

Aged↗

PubMed1995

[Value of the exercise test in the study of arrhythmia].

Exercise testing may be used to assess symptoms occurring on effort, to search for and evaluate arrhythmias or conduction defects, antiarrhythmic drugs, pacemakers or implantable cardioverter defibrillators. Interpretation of exercise testing is difficult because of the complexity of the factors in play. Exercise itself induces changes in myocardial metabolism and the autonomic nervous system, the nature and importance of which are influenced by the underlying cardiac disease and the presence of cardiac failure or myocardial ischaemia. This is particularly true when studying the behaviour of arrhythmias on effort, which depends on many parameters, in that they may appear or disappear during exercise, irrespective of their relationship to autonomic nervous system activation. The main problem lies in the interpretation of changes in the heart rate before the onset of an arrhythmia. The sinus rhythm is both a passive indicator of the vago-sympathetic equilibrium and one of the determining factor of the arrhythmia (relationship to the rate), but it is, itself, dependent on the presence of myocardial dysfunction, a source of arrhythmias, and its changes then become difficult to interpret. These reasons explain why exercise testing is certainly a valuable tool in assessing arrhythmias but the poor reproducibility, especially in the evaluation of ventricular arrhythmias, advises prudence in the interpretation of results.

Arrhythmias, Cardiac↗

PubMed1994

[Catheter ablation of atrioventricular nodal reentrant tachycardia].

Electrophysiological data of atrioventricular nodal reentrant tachycardia recensed over the last 40 years in the animal and in man has not resolved the question as to the exact site of the reentry circuit: an exclusively intranodal pathway or a pathway involving part of the atrium? The remarkable efficacy of modern radical therapy of this arrhythmia with preservation of atrioventricular conduction reinforces the concept of reentry involving not only the atrioventricular node but also the juxta nodal atrium and the superior and inferior atrionodal connections. Radical treatment was initially surgical and then by catheter ablation. The technique of specific ablation of the rapid anterior pathway was the first to be described. Its limitation is the relatively high risk (about 10%) of complete atrioventricular block. Very quickly, radiofrequency ablation of the slow posterior pathway became the method of reference. Most patients do not have retrograde conduction in the slow pathway. The pathway is located in sinus rhythm by recording its specific potentials: either the rapid potential described by Jackman et al or the fragmented potential described by Haïssaguerre and Warin. The former is recorded from the posterior septal position anterior to the orifice of the coronary sinus; the second is recorded at the same level but slightly above in the mid septal position. Ablation of the slow pathway can be performed on these purely anatomical criteria. Using these approaches, an immediate success rate of over 90% may be obtained. The recurrence rate is 0 to 5%; that of complete atrioventricular block ranges from 0 to 4%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

[Right accessory pathways with slow and decremential anterograde conduction. Electrophysiological changes during ablation of the proximal atrial poles].

Right sided accessory pathways with slow and decremential anterograde conduction differ from the anatomical substrates of the nodo-ventricular connections described by Mahaim. The connection may also be atrio-ventricular or atrio-fascicular. The authors report a series of 6 patients (2 men, average age 31 +/- 9 years) with antidromic reciprocating tachycardia implicating accessory pathways with decremential conduction (wide QRS complexes with left bundle branch block) the radiofrequency ablation of which was centered on the proximal atrial pole. The increment of pre-excitation was 75 +/- 18 ms. No nodo-ventricular or nodo-fascicular connections were observed. One patient had an atrio-ventricular connection, the mapping and ablation (5 applications) of which were performed on the annulus, as if it were a bundle of Kent. Five patients had a nodo-fascicular connection which was masked during sinus rhythm. The localisation of the proximal atrial insertion on the tricuspid annulus was initially estimated by studying the superior junction of the circuit and by endocavitary stimulation, and then by recording the M potential (activation of the accessory pathway). This was recorded in 4 patients, either at a specific point on the annulus (lateral or postero-lateral) which was the target of ablation (3 patients, 5 +/- 3 applications) or over a wider region (2 cm) at which ablation failed (1 patient: 13 applications). The site of the increment was determined in 2 patients and was proximal to the M potential. The M potential could not be recorded on the annulus in one patient. In 2 patients, the M potential was also recorded along the side of the pathway on the antero-lateral wall of the right ventricle of the tricuspid valve at its distal pole. In 2 patients, ablation was centered on the distal pole in second intention, near to the terminal part of the right bundle where it was localised in one of the two (18 applications). Finally, ablation was obtained in 5 out of 6 patients. They remain asymptomatic after 12 +/- 7 months follow-up. These cases show that accessory pathways with slow decremential conduction usually behave like a complete conduction pathway with an accessory laterally situated atrioventricular node on the tricuspid, an accessory bundle and a distal insertion which are all accessible to ablation.

Adolescent↗

PubMed1994

[Value of searching ventricular late potentials in patients recovering from ventricular fibrillation].

The prognostic value of ventricular late potentials (VLP) was studied in 38 survivors of ventricular fibrillation (VF) resuscitated after cardiac arrest. Thirty-seven patients had coronary artery disease, 24 within one month of myocardial infarction, and one patient had valvular heart disease. There were 7 deaths within 2 years, including 5 sudden deaths, the average follow-up in the remaining patients being 46 +/- 30 months. Bad prognostic factors included low left ventricular ejection fraction, anterior myocardial infarction, VF occurring after the first 24 hours of myocardial infarction and the presence of VLP. The 2 year mortality rate was 35% in patients with VLP compared with only 5% when they were absent (p < 0.05). The subgroup with the highest risk of death was that of anterior myocardial infarcts with VLP (45% 2 year mortality). The clinical circumstances surrounding VF were important; patients with clinical and electrical signs of ischaemia at the time of VF tended to have a better prognosis than the others, especially in the absence of VLP: in this subgroup of 12 "ischaemic" VFs without VLP the mortality at 2 years was nil, whereas the other 26 patients had a 27% death rate (0.05 < p < 0.10). Programmed ventricular stimulation was only carried out in 14 cases: it showed that the long-term mortality was very high (60%) in patients with VLP and inducible ventricular tachycardia (VT). Therefore, the implantation of an automatic defibrillator device would seem to be justified in patients resuscitated from VF who have both VLP and inducible VT, but of no value in cases of "ischaemic" VF without VLP.

Action Potentials↗

PubMed1992

[Pro-arrhythmia effect of pyridostigmine. Apropos of a case].

A coronary patient with myasthenia gravis with a previous myocardial infarction presented with severe ventricular arrhythmias after the replacement of neostigmine by pyridostigmine for the treatment of the myasthenia. These arrhythmias were resistant to antiarrhythmic therapy associating betablockers and amiodarone throughout treatment with pyridostigmine but regressed when this drug was withdrawn. A test of reintroduction of pyridostigmine under medical surveillance led to the reappearance of the ventricular hyperexcitability, so confirming the responsibility of this drug. This would seem to be the first reported case of severe ventricular arrhythmias due to a proarrhythmic effect of pyridostigmine. The possible mechanisms of this effect are discussed.

Coronary Disease↗

PubMed1992

[Value of signal-averaged electrocardiogram in ventricular arrhythmia without apparent heart disease].

Signal-averaged electrocardiography was performed in 132 subjects with various ventricular arrhythmias without clinically apparent heart disease and compared with the results obtained in a series of 45 normal subjects. The latter enabled definition of the following criteria of normality: QRS duration after averaging < 113 ms; Simson vector of the last 40 ms (RMS40) > or = 17 microV; low amplitude signal duration over 40 microV < 38 ms for a high pass bidirectional filter of 40-300 Hz. Complementary investigations (echo or angiography), performed in all cases, showed underlying abnormalities in 26 patients: 13 right ventricular dysplasias, 7 cardiomyopathies, 3 mitral valve prolapses and 3 minor congenital heart defects. These investigations were normal in the remaining 106 subjects. Of the 26 patients with cardiac disease, 15 had 3 criteria of positivity for late ventricular potentials, 6 had 2 criteria and the other 5 had no criteria of late ventricular potentials. Therefore, 81% of cases with cardiac disease had at least 2 diagnostic criteria of late ventricular potentials whereas only 4% of those without cardiac disease, and in the control group, had criteria of positivity (p < 0.001). Using these criteria, the predictive value of signal-averaged electrocardiography for the detection of underlying cardiac disease was good when 2 criteria are required for diagnosis of late ventricular potentials: sensitivity 81%, specificity 96%; predictive value of a positive test 78%, predictive value of a negative test 97%. Signal-averaged electrocardiography is therefore a good non-invasive method of diagnosing underlying cardiac disease in patients with ventricular arrhythmias without clinically apparent heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Long-term follow-up after sustained monomorphic ventricular tachycardia: Causes, pump failure, and empiric antiarrhythmic therapy that modify survival.

We analyzed the actuarial cardiac mortality rate of 295 consecutive patients with sustained monomorphic ventricular tachycardia who were referred to us between 1978 and 1988. Patients were divided into four groups: group I of 156 patients with coronary disease, group II of 55 patients with nonischemic left ventricular disease, group III of 65 patients with right ventricular disease, and group IV of 19 patients without detectable heart disease. Patients were treated empirically according to a prospective schema: (1) class I antiarrhythmic drugs, (2) in case of recurrence of ventricular tachycardia: amiodarone or beta-blockers, (3) in case of recurrence of ventricular tachycardia: drug combinations or surgery. The mean follow-up duration was 61 +/- 40 months after the first occurrence of ventricular tachycardia, and the clinical outcome was known in 67.5% of patients at 5 years. The actuarial mortality rates were considerably higher in groups I and II compared with those in groups III and IV (p less than 0.01). The mortality rate was slightly higher in group I than in group II (p less than 0.05). In groups I and II, actuarial mortality rate were much higher when left ventricular ejection fraction was less than 0.30 (p less than 0.01). Comparisons between treatments showed no difference in actuarial mortality rates in patients with ventricular tachycardia and left ventricular ejection fraction greater than 0.30.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

PubMed1991

Heart rate variability in left ventricular hypertrophy and heart failure, and the effects of beta-blockade. A non-spectral analysis of heart rate variability in the frequency domain and in the time domain.

An analysis of heart rate (HR) variability (HRV) was based on quantifying the number and amplitude of HR fluctuations over long (8-30 cycles) and short (2-4 cycles) sequences of acceleration and deceleration-forming oscillations. The 'product' (number times amplitude) is an equivalent of the power spectrum in the frequency domain. In the time domain, positive correlations with HR were found for the number of long (L) sympathetic-mediated oscillations, whereas they were negative for short (S) vagally-mediated oscillations. The L/S ratio, an index of the autonomic nervous system (ANS) balance, closely paralleled the circadian HR values. HRV was studied in the ambulatory ECG of three groups of 15 normal adults (group I), 13 patients with left ventricular hypertrophy (LVH, group II) and 13 patients with heart failure (HF, group III). In basic conditions the mean HR was 77.1 +/- 1.9 beats min-1 (mean +/- SEM) in group I, 76.8 +/- 3.3 in II, 79.5 +/- 3.5 in III (P = NS). The different types of oscillations had smaller 24-h average values of the product in groups II and III than in group I, but the trends did not reach significance. However, the pooled 24 hourly values of the L/S ratio in group I (1.17 +/- 0.09) were lower than in group II (1.33 +/- 0.06, P less than 0.05 at Ancova) and higher than in group III (1.06 +/- 0.09, P less than 0.001). A 3-day treatment with acebutolol non-uniformly slowed the mean HR:--9.5% in group I, --18.1% in II and -19.1% in III (P less than 0.001), and uniformly diminished the L/S ratio by 17% to 20% (P less than 0.01). In conclusion, the sympathetic predominance of the ANS balance in LVH and HF is reflected by the beta-blockade induced HR decrease that is twice as marked in patients as in controls. In basic conditions HRV tends to be depressed in LVH and even more in HF. The ANS imbalance, however, has different modalities depending on the presence of HF, probably because of the different status of beta-adrenergic receptors in this condition.

Acebutolol↗

PubMed1991

[Life expectancy after a first attack of sustained monomorphic ventricular tachycardia. Apropos of 295 patients with a follow-up of more than 5 years].

Analysis of actuarial cardiac mortality of 295 patients after a first attack of sustained monomorphic ventricular tachycardia followed up for an average of 5.1 years showed that: the aetiology was the main prognostic factor. Patients with a normal left ventricle had a zero 5 year mortality rate (normal heart) or 3% (arrhythmogenic right ventricular dysplasia) compared with 24% in patients with cardiomyopathy and 40% with myocardial infarction: p less than 0.01. Similar results were obtained if sudden death was considered; in patients with left-ventricular disease, the role of pump function assessed by the ejection fraction was essential: the 5 year mortality was 14.5% (cardiomyopathy) and 30% (myocardial infarction) if this was greater than 0.3 compared to 43% and 51% respectively when less than 0.3 (p less than 0.01); the heart rate of spontaneous ventricular tachycardia and that of tachycardia induced during endocavitary investigation had no influence on the mortality. However, the mortality following a first tachycardia with syncope was higher than that following a well tolerated tachycardia (p less than 0.5 if the ejection fraction less than or equal to 0.3 and p less than 0.001 if greater than 0.3).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

PubMed1990

[Signal-averaged electrocardiography in right ventricular dysplasia].

The authors report their experience of signal-averaged electrocardiography (SAE) in arrhythmogenic right ventricular dysplasia (ARVD) in a study comparing the results in 40 control subjects, 21 patients with ARVD with episodes of sustained monomorphic ventricular tachycardia (VT) (Group I), 7 patients with ARVD without sustained VT (Group II) and 10 asymptomatic members of the families of patients in Group I (Group III). There were significant differences in the results of SAE in the time domain between the control group and Group I, patients with "classical" ARVD. The RMS 40 (root mean square of the last 40 ms of the QRS complex) was the most sensitive parameter but the specificity was less than the averaged QRS width and the low amplitude signal duration. The results in Group II were more varied, some patients having clearly abnormal SAE and others strictly normal recordings. In Group III, the investigation was normal. Spectral analysis after Fourier transformation did not show significant differences between the 3 groups. A difference was observed between the diffuse and localised forms of ARVD in Groups I and II: the localised forms had a shorter QRS width and low amplitude signal duration than the diffuse forms. Also, there was a relationship in Group I between age and duration of QRS and delayed potential which increased and with the RMS 40 or 50 which decreased. This is an argument in favour of the progressive nature of ARVD with respect to time.

Adult↗

PubMed1990

[Late potentials and arrhythmogenic right ventricular dysplasia].

The authors report on their experience in investigating late potentials (LPs) in arrhythmogenic right ventricular dysplasia (ARVD), by comparing 35 patients with ARVD with 40 control subjects. The values of QRS and RMS40 and the duration of the LP showed a marked difference between the control group and the ARVDs, particularly if sustained VT was present. In this case, 68 per cent of patients were found to have LPs (with at least 2 out of 3 parameters abnormal) versus 50 per cent in the ARVDs without sustained VT and 5 per cent in the controls. There was a difference between the diffuse forms (10 per cent) and the localized forms (25 per cent) of ARVD: the LPs were markedly more obvious in the diffuse forms. Likewise, there was a clear relationship between age and the criteria for LPs in ARVD with sustained VT. This is an argument in favour of the evolutive character of the disease, which could be observed directly in a few cases in which the examinations were repeated over the course of time.

Adult↗

PubMed1989

Surgery for the Wolff-Parkinson-White syndrome in 73 consecutive patients: what have we learnt from intraoperative mapping?

Intraoperative epicardial mapping data obtained in 73 consecutive patients operated upon for the Wolff-Parkinson-White syndrome were reviewed. Fifty-six patients had single and 17 patients had multiple accessory pathways. Except for right free wall pathways, all bypass tracts were divided using an endocardial approach. There were 2 operative deaths, 1 of which occurred after a concomitant mitral valve replacement. A total of 78 of the 87 pathways present in the 71 survivors were successfully ablated (90%). All failures occurred in patients with left posterior septal pathways. Epicardial mapping performed prior to bypass was found helpful in identifying multiple distinct accessory pathways which had been missed preoperatively. This occurred in 6 patients and led to appropriate combinations of classic operative approaches which resulted in all of these pathways being successfully divided. Further, by demonstrating that Kent bundles often presented as multiple closely-spaced or arborized accessory pathways, intraoperative mapping led to widening of the margins of surgical dissection, and in particular to an additional left atriotomy in all cases of left posterior septal accessory pathways which resulted in a substantial improvement in our rate of success.

Adolescent↗

PubMed1989

[The autonomic nervous system in sudden infant death syndrome. Analysis of heart rate and sinusal variability on Holter monitoring of infants who died].

To evidence abnormality of cardiac control by the autonomic nervous system in the sudden infant death syndrome (SIDS) we retrospectively analysed the Holter recordings and cardiopneumograms of 19 infants (11 boys, 8 girls) of mean +/- SD age 2.3 +/- 1.5 months who had subsequently died of SIDS. Two infants were regarded as normal and the reference diagnoses in the remaining 17 infants were: apparent life threatening event (8), SIDS siblings (8) and prematurity (1). At the time of death the age was 4.2 +/- 2 months. Each of these infants was matched with three control infants in term of postnatal age, gestational age and reference diagnosis, but without SIDS at follow-up of at least one year. Nine hours of Holter recordings (9 p.m. to 6 a.m.) were analysed in term of mean heart rate and sinus oscillations waves. To differentiate between short oscillations of 4 to 6 RR, which are induced by respiration and reflect vagal activity, and long oscillations of 20 to 32 RR, which reflect both neurogenic sympathetic and vagal activity, we used a new method which measures the number and the amplitude in milliseconds of each type of oscillations. The results are expressed as the logarithm of the product of these two variables. Heart rate, correlated to age in both groups, is higher in the deceased infants group (141 +/- 14 mn and 135 +/- 15; p less than 0.05: analysis of covariance with age as an independent variable). Short oscillations, also correlated to age, are lower in the deceased infants group (3.35 +/- 0.59 and 3.65 +/- 0.61; p less than 0.05: analysis of covariance with age).(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmia, Sinus↗

PubMed1989

[Sinus rhythm and standard deviation in cardiac cycles. Influence of myocardial status and beta-blocker treatment].

The efficacy of beta-blockers in preventing sudden death after myocardial infarction would seem to be greater in patients with cardiac failure and proportional to the reduction in heart rate induced by these drugs. In addition, a reduction in heart rate variability measured by the standard deviation from the average cardiac cycle over 24 hours has been reported to be an independent bad prognostic factor after myocardial infarction. This study compares the heart rates and the standard deviations from the mean cardiac cycle over 24 hours in 41 patients divided into 3 groups of comparable age (group I: normal subjects, n = 15; group II: hypertrophic cardiomyopathy without cardiac failure, n = 13; group III: cardiac failure, n = 13) before and after administration of acebutolol (10 mg/kg). The average 24 hour heart rates, the maximum 8-hour diurnal and minimum average 4-hour nocturnal heart rates, day-night ratio and standard deviations from the average 24 hour heart rate and at the hours of maximum and minimum average heart rates were measured by Holter monitoring with an ATREC II system. The 24 hour heart rates were slower in groups II (-18.1 p. 100) and III (-19.1 p. 100) than in group I (-9.5 p. 100), p less than 0.01, the basal heart rates being comparable and the heart rates after acebutolol being significantly lower in groups II and III. The degree of change was comparable during the diurnal and nocturnal periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Acebutolol↗

PubMed1988

Results of electrical fulguration in arrhythmogenic right ventricular disease.

Eleven patients with sustained ventricular tachycardia (VT) refractory to antiarrhythmic drugs due to right ventricular disease shown by angiography underwent fulguration. Seven patients always had VT with the same morphology, and 4 had clinical VT with 2 or 3 different QRS waveforms. Five patients underwent a single fulguration and the other 6 underwent from 2 to 5 procedures; 2 to 14 shocks (mean 6) of 150 to 250 J were used. No serious complications occurred. At 31.5 +/- 9 months of follow-up, the arrhythmia was controlled in 8 patients, with continuation of previously ineffective antiarrhythmic drug therapy in 6 of 8. The number of VT episodes the year before and after fulguration was 0.5 +/- 0.7 vs 3.5 +/- 1.7 (p less than 0.001). There was no statistically significant difference between the success rate and the degree of prematurity of the onset of the local electrogram during VT: -36 +/- 31 ms for successes and -38 +/- 13 ms for failures. In 7 patients with monomorphic VT, there were 6 successes and 1 failure, and in 4 patients with several morphologies of VT, there were 2 successes and 2 failures (1 due to the appearance of a "new" VT). Thus, electrical fulguration of VT in patients with right ventricular disease is safe and most often effective, particularly in patients with monomorphic VT, when combined with antiarrhythmic drugs. In these patients, the usually recommended endocardial mapping criteria for the determination of the optimal fulguration site were not predictive of outcome. Further studies are necessary to better define the optimal site for fulguration.

Adult↗

PubMed1988

Respective role of sympathetic tone and of cardiac pauses in the genesis of 62 cases of ventricular fibrillation recorded during Holter monitoring.

Sixty-two Holter recordings of sudden death due to ventricular fibrillation (VF) were analysed by full disclosure and computerized processing. Thirteen sudden deaths were due to torsades de pointes in noncoronary subjects (11/13), related to quinidine-like drugs and/or hypokalaemia: they were always initiated by a long RR cycle due to a post-extrasystolic pause, and announced by a progressive decrease of mean heart rate (from 77.5 +/- 2.5 to 60.6 +/- 2.7 beats min-1, P less than 0.001), in the three preceding hours. The other cases occurred in coronary patients (45/49), with acceleration of ventricular tachycardia (VT), monomorphic in 24 cases, polymorphic in 13, the ventricular rate increasing from 220.6 +/- 55 to 241.5 +/- 69 beats min-1, rather than with primary VF (12 cases). A cardiac pause (RR cycle exceeding 125% of the mean five preceding cycles) was present in 22/49 cases immediately before the onset of VT/VF. The coupling interval of the extrasystole initiating VT/VF was shorter than the shortest value encountered before: 377.6 +/- 94.5 ms vs 421.4 +/- 92.3. The prematurity index (coupling interval/preceding RR cycle ratio) was lower in primary VF than in VT leading to VF. In the last hour preceding VF, ST changes were unusual (five cases), whereas heart rate increased from 82.8 +/- 20 to 92.0 +/- 26.7 beats min-1, (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗