Biomedical subjects
Publications and source records attributed to M Guarnerio.
Severe stenosis of right and left main coronary artery ostia developed after aortic root reconstruction with gelatin-resorcin-formol glue for correction of acute type A aortic dissection. Surgical treatment of this condition required grafting of the right and left anterior descending arteries with bilateral mammary arteries on the beating heart.
We report our experience with flecainide and propafenone therapy for inducible supraventricular tachycardias and paroxysmal supraventricular tachycardias due to atrioventricular (AV) nodal reentry or the Wolff-Parkinson-White syndrome. We performed an electropharmacologic test (ET) that consisted of first inducing a clinical arrhythmia by transesophageal atrial pacing (TAP) protocol. This was followed by intravenous drug administration and TAP reevaluation, either after acute intravenous administration or in oral steady-state. We used ET with flecainide and/or propafenone to study 2 groups of patients at least 3 years before the long-term clinical observation period. The first group was comprised of 58 patients with reciprocating tachycardias--due to AV node reentry in 17 (29.3%) and anomalous pathway in 41 (70.7%). Twelve (29.3%) of the latter had reciprocating tachycardias, 15 (36.6%) had atrial fibrillation, and 14 (34.2%) had both arrhythmias. During ET, flecainide was administered to 42 patients, and the ET was considered positive in 28 (66.7%). Propafenone was administered to 32 patients, with positive results in 15 (46.9%). In 15 patients, both flecainide and propafenone were tested, 8 receiving flecainide after a negative ET with propafenone, and 7 receiving propafenone after a negative ET with flecainide. In the first group, the ET was positive in 7 (87.5%), and in the second group, it was positive in 3 (42.9%). In a follow-up of 40.1 +/- 11 months, 38 (65.5%) patients had positive outcomes, 5 (8.6%) had to stop receiving the drugs because of side effects, 3 (5.2%) stopped because of inefficacy, and 12 (20.7%) dropped out.(ABSTRACT TRUNCATED AT 250 WORDS)
Sixty-eight patients with disabling episodes of inducible supraventricular tachyarrhythmia were tested electropharmacologically by transoesophageal atrial pacing. Using this technique we induced clinical arrhythmia in 67 (98.5%); 26 (38.8%) had a reciprocating tachycardia due to AV node reentry and 41 (61.2%) a by-pass tract. In the latter we induced a reciprocating tachycardia in 12 (29.3%), atrial fibrillation in 25 (36.5%) and both in 14 (34.2%). We then performed an anti-arrhythmic drug test and a transoesophageal reevaluation either after acute intravenous drug administration or during oral steady state. Altogether we tested 111 drugs or a combination of drugs before the results were considered positive; all patients tolerated the procedure well and were discharged with the drug or combination of drugs judged effective. At follow-up of 16.6 +/- 8.5 months, 42 patients (62.7%) were symptom-free, 17 (25.3%) had minor and non-disabling relapses, six (9%) stopped the drug because of inefficacy (1-1.5%) or side effects (5-7.5%); two (3%) dropped out. We conclude that electropharmacological testing with transoesophageal pacing constitutes a very good approach for inducible supraventricular tachyarrhythmias: it permits selection of optimal long-term anti-arrhythmic treatment and is well tolerated, only slightly invasive and without adverse effects.
Distinctly different from the other beta-blocking agents, sotalol prolongs action potential duration in myocardial and Purkinje fibers, and increases atrial as well as ventricular effective refractory periods. Similarly, antegrade and retrograde accessory pathway refractory periods are increased by sotalol. The electrophysiologic and clinical effects of sotalol were studied in 40 patients (31 male and 9 female, mean age 32 +/- 14 years) with Wolff-Parkinson-White Syndrome (WPW). All patients had disabling episodes of supraventricular tachyarrhythmias (ST). Of the 40 patients, 15 (37%) had spontaneous recurrence of paroxysmal supraventricular reciprocating tachycardia (PSRT), 14 (35%) of atrial fibrillation (AF) and 11 (28%) of both PSRT and AF. All of the patients were non responders to serial transesophageal electropharmacological tests using I C class drugs. Sotalol 252 +/- 73 mg daily was administered, and, in steady-state, a new transesophageal study (TS) was performed to observe the re-induction of PSRT and/or AF. 34 patients (85%) were responders to TS (noninducibility of ST, or nonsustained ST or AF inducibility with an increase of 30% in the minimum R-R interval between pre-excitated beats during AF) and the results were confirmed during a follow-up of 17 +/- 9 months. In the non-responder group (5 patients), a I C class drug was associated with sotalol. One patient, who was a "non responder" to sotalol, sotalol + I C class drug, and to amiodarone, underwent surgical therapy. In the 26 patients (65%) who had episodes of PSRT (37%) or episodes of PSRT and AF (28%), it was impossible to reinduce PSRT in 85% of the cases. AF was induced at baseline in all of the studied patients, but after sotalol administration in 15 patients, it was impossible to reinduce AF. The rate of induced AF decreased from 208 +/- 39 beats/min to 156 +/- 36 beats/min (p < 0.001). The mean shortest R-R interval between pre-excitated beats increased from 214 +/- 35 (baseline) to 293 +/- 97 msec (sotalol steady state) (p < 0.001). No side effects were observed. A significant prolongation (p < 0.001) of the QTc interval was observed in all the patients after sotalol administration (from 0.39 +/- 0.2 to 0.42 +/- 0.02 sec.). On the basis of our results, we may conclude that sotalol has a potent effect on the antegrade refractoriness of the anomalous pathway and, in WPW syndrome at risk, is also effective in patients who don't respond to I C class drugs.
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The use of an antitachycardia pacemaker in the treatment of hyperkinetic supraventricular arrhythmias is founded on a reliable electrophysiological ground and on an high technology. Nevertheless the clinical impact of this approach is not considerable since the 5% to 7% of the potential candidates are in effect treated with an antitachycardia device. The success of new therapeutical procedures (i.e. catheter ablation) together with the shifting of the clinical, technical and commercial interest towards the electrical treatment of the malignant ventricular tachyarrhythmias are the main causes of the minor role that now the antitachycardia pacemakers play in the management of the patients with hyperkinetic supraventricular arrhythmias.
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UNLABELLED: Propafenone and flecainide, both I C class drugs, are first choice in the treatment of paroxysmal supraventricular reciprocating tachycardia. The aim of this study was to check whether a negative or paradoxical electropharmacological test with one of the two drugs was predictive of an equally negative or paradoxical test with the other drug. Thirty patients with disabling paroxysmal supraventricular reciprocating tachycardia, 16 M, 14 F, mean age 30.6 +/- 16 years, were studied with serial electropharmacological tests using esophageal approach. The reentry circuit was sustained by an anomalous pathway in 25 patients (83.5%) whereas it was idionodal in the other 5 (16.5%). Propafenone was tested in 13 patients (43.5%, group A) after flecainide had resulted negative or paradoxical in the first test. In 17 patients (56.5%, group B) flecainide was tested after propafenone had resulted negative or paradoxical. The second drug tested was also ineffective in 14 of the 30 patients (group A + group B) while it had positive results in 16 patients. Specifically, propafenone was positive in 6 of the 13 patients (group A) in whom flecainide had been negative, and flecainide was positive in 10 of the 17 patients (group B) with acute negative or paradoxical propafenone test. These "acute" results were confirmed in steady-state with esophageal study and in the follow-up (21.9 +/- 9.3 months). CONCLUSIONS: 53.5% of the patients who are "non responders" to the electropharmacological test with one of the two drugs (propafenone or flecainide) may be "responders" to the other drug. Thus the ineffectiveness of one of the two drugs is not predictive of ineffectiveness of the other.
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From 1985 to 1988 the authors performed 299 procedures of transesophageal atrial pacing in 162 patients with hyperkinetic supraventricular arrhythmias. The pacing abolition of atrial flutter had been mainly applied with an invasive technique. The employment of transesophageal atrial pacing received its large development, but simplified this, the probability of abolishing supraventricular tachycardia becoming lower.
Pentisomide (CM 7857) is a new class I antiarrhythmic drug whose effect on sustained ventricular tachycardia has only been slightly investigated to date. The aim of this paper is to examine the pentisomide action on selected patients with ventricular tachycardia inducible during intracavitary electrophysiological study. Thus, 12 patients (9 M, 3 F, mean age: 45.2 years, range: 24-78), all but two with detectable heart disease, underwent electropharmacological tests with pentisomide after they had resulted "non responders" (8 patients) or had had a proarrhythmic worsening effect (3 patients) to electropharmacological tests with amiodarone or flecainide or propafenone or mexiletine. After the inducibility and the reproducibility of ventricular tachycardia has been assessed in the basal state, all patients underwent several attempts to reinduce ventricular tachycardia, during the i.v. infusion of pentisomide 1.5 mg/kg/5 min followed by continuous infusion of 1 mg/kg/h, at the same time drug plasma level was assessed. Ventricular tachycardia inducibility was still inducible after pentisomide, but with a longer cycle length (446 +/- 88 versus 337 +/- 82 msec) than in the basal state (p less than 0.0025). No patients had proarrhythmic worsening effects. The pentisomide plasma level (available in 5 patients) ranged from 3.4 to 22.3 (mean 8.9 micrograms/ml). Four patients underwent chronic oral treatment (in 1 pt in association with amiodarone) with a good clinical outcome (mean follow-up 6.25 months, range 1-12). We stress the absence of proarrhythmic worsening effects and the powerful effect of the drug on ventricular tachycardia cycle length.(ABSTRACT TRUNCATED AT 250 WORDS)
Here we report on a study of 181 episodes of spontaneous atrial flutter (AF) (mean atrial cycle length 250 +/- 32 msec) treated by transesophageal atrial pacing (TAP) in 138 patients (92 men and 46 women; mean age 59.5 +/- 12.6 years). TAP was effective in 163 episodes (90%); sinus rhythm resumption was immediate in 36 (19.9%) and followed a short period of atrial fibrillation in 64 (35.3%); in 63 episodes (34.8%) a stable atrial fibrillation was obtained. TAP was unsuccessful in 18 cases (10%). All the patients tolerated the procedure well. A statistical elaboration with the Fisher exact test did not evidence a correlation between efficacy and age, sex, atrial cycle length, or underlying heart disease but showed a significant correlation between efficacy and AF duration of less than 1 day (p less than 0.05) and absence of antiarrhythmic pharmacologic pretreatment (p less than 0.01). These data strongly support the immediate first-choice use of TAP in AF therapy.
The aim of this work is to assess the reliability of transvenous high energy bi-directional shock with a triple electrode system as the initial step in implanting the automatic cardioverter defibrillator by thoracotomy. During the electrophysiological study on 12 patients, 16 different types of sustained ventricular tachycardia were treated with a 25 J bi-directional QRS synchronized shock delivered through a right ventricular apical cathode and 2 anodes, i.e., the superior vena cava-right atrium and skin patch electrode placed just above the left nipple. A Medtronic 6880 catheter, placed in the right ventricular apex, and a cutaneous patch (CRS, 50 cm2 in surface area) were connected by a cable to a Medtronic model 5350 external cardioverter defibrillator. All but one patient had coronary disease with previous myocardial infarction. The mean VT cycle length was 299 msec (min 200, max 380 ms); 5 VT types had left and 2 had right bundle branch block pattern; 9 had a "bizarre" pattern. The tachycardia was interrupted in 14 types; in 1 type (cycle length 360 msec with "bizarre" morphological pattern) ventricular fibrillation was induced by a well synchronized shock; in 1 type (cycle length 200 msec with "bizarre" morphological pattern) a badly synchronized shock induced a sustained ventricular tachycardia with a longer cycle length (360 msec); this was subsequently stopped by another shock. The transvenous high energy bi-directional shock was quite well tolerated by the patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Even today there is controversy as regards the best approach to asymptomatic or slightly symptomatic athletes with the WPW syndrome as regards fitness for sports activity, especially in some countries where the doctor is responsible for certifying sports fitness. This study concerns 84 asymptomatic or slightly symptomatic athletes (66 males, 18 females, mean age 21.7 years, range 12-44 years) who underwent a stimulation protocol the end-point of which was the induction of atrial fibrillation (or, if not possible, atrial tachyarrhythmia) in the basal state and during bicycle stress test with transesophageal atrial pacing. The 81 athletes in whom the end-point was reached were divided into two groups: Group I includes the 32 athletes with the shortest R-R interval between pre-excited beats less than or equal to 240 ms in the basal state and/or less than or equal to 210 ms during bicycle ergometer test, Group II includes the other 49 patients. The evaluation during exercise was not carried out in four athletes because of serious haemodynamic compromise due to the arrhythmia induced in the basal state. Only 21/32 athletes would have been included in Group I if only evaluated in the basal state. In 30/81 athletes (37%), there was discrepancy between the result of stimulation and the result of the usual non-invasive evaluation (Holter monitoring, ergometric stress test, ajmaline test). On average, 40 min are required for the performance of the study protocol except when the induced arrhythmia lasts more than 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)
The most suitable approach to the athletes with WPW is controversial. Therefore 66 symptom-free athletes with WPW and without heart disease (53 M, 13 F, mean age 21.98 yrs, min 12--max 44) underwent a study protocol whose end-point was the induction of supraventricular tachyarrhythmia, i.e. atrial fibrillation or, if not possible, atrial flutter or atrial tachycardia at rest and during ergometric stress test. The athletes with shortest R-R interval between preexcited beats less than or equal to 240 ms at rest and/or less than or equal to 210 ms during exercise were judged as being at risk i.e. no fit for sport activity. The end-point was reached in 64/66 athletes (in 62 atrial fibrillation). In 4 athletes with life threatening arrhythmia induced at rest the evaluation during exercise was not performed. According to the evaluation at rest we were able to identify only 18 athletes (28.1%) as being at risk, while according to the complete study protocol 26 athletes (40.6%) were judged as such. In 23/64 athletes (36%) this judgement was discordant with the usual non invasive evaluation (i.e. Holter monitoring, ergometric stress test, ajmaline test). During induced atrial fibrillation no significant difference, was found between the percentage of preexcited beats at rest and during exercise. On the average, 40 min. are required for performance of this study protocol (if the induced arrhythmia lasts less than 5 min.). According to our results we conclude: a) the non invasive assessment of the WPW athletes is unsatisfactory; b) the induction of atrial fibrillation during exercise gives a remarkable increase of the diagnostic power with respect to the assessment only at rest; c) since it is simple to perform and not expensive (in time, staff and cost) and because of its high diagnostic yield, we regard this protocol as fundamental for the electrophysiological evaluation of WPW athletes and also suitable for systematic study of WPW patients.
Here we report on the case of a patient with idiopathic complete AV block and ventricular ectopic beats in basal state. The patient had been asymptomatic until the age of 50 and then suddenly began to suffer from relapsing episodes of syncope, related to "Torsade de Pointe" and Ventricular Fibrillation (hypokalaemia was present at the same time). We deal with the prognostic significance of ventricular ectopic beats and we make the hypothesis that hyperkinetic ventricular arrhythmias play a role in the origin of the symptoms of patients with congenital or idiopathic complete AV block. Finally, we discuss the limits of the therapeutic effectiveness of permanent pacing in these cases.
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We report a case of partial persistent atrial standstill from a group of patients with familial endemic complete or partial persistent atrial standstill. In this patient we observed the evolution from sinus rhythm (with episodes of uncommon atrial flutter treated by electrostimulation) to the typical clinical picture of partial persistent atrial standstill, which is described also in its electrophysiological features. Incomplete and complete persistent atrial standstill may represent different stages of the same disease of the atrial wall.