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Biomedical subjects

C Moro

Publications and source records attributed to C Moro.

At least 55 records · Page 3Linked to original sources
PubMed1992

Cardiac fulguration, a new alternative therapy for atrioventricular nodal reentrant tachycardia.

Ten patients underwent endocardial catheter ablation of the atrioventricular junction for atrioventricular nodal reentrant tachycardias. Unipolar cathodic discharges at the distal electrode were administered against an external plate. Bipolar His and atrial deflections showed a mean of 0.15 mv and 0.5 mv respectively. Mean total energy used per patient was 195 J (range: 50-750), with a mean number of ablating discharges of 2.0 per patient, (range: 1-5). Complete atrioventricular block was achieved, but conduction reappeared in all except one patient, after a mean interval of 19.9 min. Electrophysiological evaluation was assessed 3-8 days after ablation. Sustained atrioventricular nodal reentrant tachycardias were no longer inducible in any patient. Retrograde conduction was abolished in six, and was slow and decremental in four. First-degree atrioventricular block, with intranodal delay was diagnosed in six, with an AH interval that ranged from 240 to 130 ms. Mean cycle length for appearance of Wenckebach atrioventricular block was 390 ms after ablation. One patient developed complete atrioventricular block after two discharges of 50 J, another required a repeat ablation for recurrence of intranodal tachycardia and also developed complete anterograde block in a new session of ablation with a 150 J discharge. In these two patients permanent pacing was needed. Eight patients were cured after a mean follow-up of 20 months. Less energy and fewer discharges should be administered to abolish functional dissociation of the atrioventricular node, without complete interruption of anterograde conduction.

Adult↗
PubMed1992

Atrial fibrillation in Wolff-Parkinson-White syndrome: reversal of isoproterenol effects by sotalol.

Sotalol has Class II and III antiarrhythmic effects. Its efficacy and safety as a treatment of atrial fibrillation in patients with the Wolff-Parkinson-White (WPW) syndrome is controversial. We evaluated the effects of isoproterenol and IV sotalol (1.5 mg/kg in 10 minutes) given together versus isoproterenol alone on anterograde conduction through the AV node and accessory pathway. Atrial fibrillation was induced in 22 patients with WPW (13 men, 9 women, 36 +/- 16 years old). AV node and accessory pathway conduction were both enhanced by isoproterenol, although the effect was greater on the AV node. The minimum interval between preexcited QRS complexes shortened in all patients. Conversely, sotalol caused a significant prolongation of the shortest preexcited QRS interval as well as of the shortest interval between narrow QRS complexes. In addition, sotalol reversed all the effects of isoproterenol during atrial fibrillation. The percent of preexcited QRS complexes was not significantly modified because variations in ventricular preexcitation results from a balance between the relative effects on refractoriness of the accessory pathway versus of the AV node and in the amount of respective anterograde and retrograde concealed conduction. There were no serious adverse effects. Reversion to sinus rhythm was documented in 12 patients (60%). These short-term observations suggest that sotalol may be safe and effective in the treatment of patients with WPW and atrial fibrillation.

Adult↗
PubMed1992

[The interruption of atrioventricular conduction by cardiac fulguration in patients with supraventricular tachycardias. The mid- and long-term results].

Catheter ablation of the atrioventricular node is a therapeutic technique for the treatment of patients with drug-refractory supraventricular tachyarrhythmias. In our Arrhythmia Unit 25 patients (8 women, 17 men) aged (mean +/- DE) 56 +/- 10 years have undergone fulguration of the atrioventricular junction since 1986. The more frequent treated rhythm disturbance was atrial flutter or fibrillation, with uncontrolled rapid ventricular response. Absence of organic heart disease was diagnosed in 9 patients; the remainder had valvular heart disease (2), cor pulmonale (2), cardiomyopathy (7), hypertensive heart disease (2) and Wolff-Parkinson-White syndrome (3). Under general anesthesia 1.8 +/- 0.8 shocks/patients were delivered along 1.2 +/- 0.7 sessions/patient. In 23 of 25 patients (92%) complete atrioventricular block was achieved, and a pacemaker was implanted. There were no complications. The other 2 patients were referred to surgery for cryoablation of the atrioventricular junction. Patients were followed for an average of 21 +/- 12 months. Four patients have died: two due to congestive heart failure, which was present prior to the ablation procedure, the third because of a metastatic carcinoma, and the fourth had a sudden death 14 months after the procedure (he had dilated cardiomyopathy and Wolff-Parkinson-White syndrome). The remainder in chronic stable complete atrioventricular block are asymptomatic for arrhythmias and without antiarrhythmic medication.

Adult↗
PubMed1990

[Prognostic significance of silent ischemia in the exercise test in patients with coronary disease].

To evaluate the prognostic significance of silent ischemia during exercise testing, 152 consecutive patients (143 males, 9 females) with a mean SD of 55 +/- 7 years (age range 32-73) who underwent exercise testing and coronary arteriography within 3 months were studied. All patients had the following characteristics: 1) a positive electrocardiographic exercise test response; 2) significant coronary artery disease on the arteriography; 3) uninterrupted clinical follow-up for a minimum of 6 months. The 152 patients were divided in 2 groups: group I: 56 patients (37%) with ischemic ST-segment depression during exercise testing without angina (silent ischemia); group II: 96 patients (63%) with ischemic ST-segment depression and angina (symptomatic ischemia). Patients in group I and group II showed similar time to ST-segment depression (3.6 +/- 1.5 min vs 3.2 +/- 1.4 min; p = NS), maximal ST-segment depression and peak heart rate-systolic pressure product (21,151 +/- 7,124 vs 20,456 +/- 6,024; p = NS). Exercise duration was longer in group I than in group II (5.6 +/- 2.1 min vs 4.8 +/- 1.5 min; p less than 0.001). The extent of coronary artery disease defined by the number of significant narrowed coronary vessels, left ventricular end diastolic pressure and ejection fraction were similar in the 2 groups. Sixty six patients who underwent coronary bypass surgery were not included in the analysis. The remaining 86 patients (40 in group I and 46 in group II) were medically treated. The mean follow-up period was 43,5 +/- 25 months (range 6-101).2+ myocardial ischemia during exercise testing.

Adult↗
PubMed1990

[Validation of the Holter method in detecting myocardial ischemia using an exercise test simultaneously].

UNLABELLED: To evaluate the reliability of Holter monitoring in reproducing myocardial ischemic changes, 110 patients (90 males, 20 females; age range: 14-74 years) underwent a Bruce protocol treadmill exercise test. An electrocardiogram was recorded simultaneously with a two-channel modulated Holter recorder (frequency response: 0.05-100 Hz) with bipolar CM-V3 and CM-V5 leads and by a conventional 12-lead system. An ischemic ST-segment change was defined as 1 mm or more ST-segment depression lasting more than 0.08 sec after the J point. Results were concordant in 101 patients, 36 with both positive and 65 with both negative responses. Eight false negative and one false positive Holter ischemic episodes occurred. This yielded an accuracy (expressed as sensitivity, specificity, positive and negative predictive values) of 81.8%, 98.5%, 97.3% and 89.0%, respectively. There was a good correlation between the maximal ST-segment depression (r = 0.57; p less than 0.001), duration of ischemia (r = 0.89; p less than 0.001), heart rate at the onset of the ischemic episode (r = 0.91; p less than 0.001) and maximal heart rate (r = 0.98; p less than 0.001). CONCLUSIONS: Two-channel amplitude modulated Holter recording system with bipolar CM-V3 and CM-V5 leads can reliably reproduce ST-segment changes.

Adolescent↗
PubMed1989

Dose related efficacy of adenosine triphosphate in spontaneous supraventricular tachyarrhythmias.

Intravenous adenosine triphosphate has been proved to be useful for the treatment of supraventricular tachyarrhythmias. The optimal dose to be employed, however, has yet to be stated. Forty-two episodes of spontaneous paroxysmal supraventricular tachycardia, observed in 33 patients (16 men and 17 women, mean age 51 years) were treated with intravenous boluses. These were given in 10 mg increments at increasing doses from 10 to 50 mg at intervals of three minutes if the arrhythmia persisted despite the previous dose. When using a dose less than or equal to 40 mg, tachycardia was terminated in 37 of 42 episodes in less than 50 seconds. In four of the remaining five, atrial flutter and ectopic atrial tachycardia were diagnosed after administration of adenosine triphosphate. The other patient was subsequently found to have an atrioventricular reentrant tachycardia incorporating two accessory pathways. More than half of the treated episodes of supraventricular tachycardia terminated with the minimal dose of 10 mg and 7.1% required 40 mg. In five patients, arrhythmia ceased and reappeared despite the use of adenosine triphosphate. All the patients experienced an unpleasant feeling of dyspnoea or suffocation after injection of the drug. Sinus pauses and bradycardia following termination of the arrhythmia were directly correlated with the dose employed (P less than 0.05). We conclude that adenosine triphosphate is a useful, safe and effective drug at low dose in correctly diagnosed reentrant tachycardias involving the atrioventricular node. It is also useful as a diagnostic tool in patients with supraventricular tachyarrhythmias.

Adenosine Triphosphate↗
PubMed1989

Thrombus apposition on catheter ablation injuries.

64 ablation catheter-induced injuries were studied macroscopically and microscopically to determine the incidence of endocardial thrombus formation. Ablation was performed in 16 mongrel dogs, 7 days before necropsy, 16 endocardial necroses were located in the right atrioventricular (AV) junction, 16 in the non-coronary cusp of the aortic valve or the subaortic valve area, 16 in the right and 16 in the left ventricle. Cathodal discharge at the distal electrode was employed against an external anodal plate for ventricular ablation. Necroses in the right AV junction and in the aortic area where the result of transseptal His bundle ablation. Energies ranged from 100-360 J. Pathologic examination was performed 1 week after ablation. 13 thrombi were observed attached to the endocardial necrosis area, of sizes ranging from 1-25 mm diameter (mean 6.9 mm). Six thrombi were found in the septal valve of the tricuspid valve, two in the aortic valve, two in the subaortic region, and three related to ventricular necroses. We conclude that the incidence of thrombosis is 20% in ablation injuries, the majority, 77%, having a diameter less than or equal to 10 mm. No correlation was found between thrombus formation and delivered energy or catheter polarity.

Animals↗