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Biomedical subjects

P Santarelli

Publications and source records attributed to P Santarelli.

At least 19 recordsLinked to original sources
PubMed1991

Surgical treatment of cardiac arrhythmias.

This report describes 20 consecutive patients who underwent surgical procedures for treatment of cardiac arrhythmias. 16 patients have been operated for WPW syndrome, always using the epicardial approach, without extracorporeal circulation. Three patients underwent surgery for atrio-ventricular nodal reentrant tachycardia, using a discrete perinodal cryotreatment, during normothermic extracorporeal circulation. In one case we used cryoablation of the atrial myocardium below the coronary sinus to treat atrial flutter. This operation was performed under normothermic extracorporeal circulation. In our observations, there was no early or late death; postoperative complications developed in 1 patient (5%) due to pericarditis. Ablation of the AP was completely successful in all the cases (100%) operated for WPW as well as for AVNRT syndromes and atrial flutter.

Arrhythmias, Cardiac↗
PubMed1991

Comparison between two versus three patches single pulse shock defibrillation in pigs.

The aim of the study was to test the hypothesis that defibrillation with a single pulse shock can be obtained at lower energy using three epicardial patches configuration (one cathode and two anodes) instead of the conventional two patches. The total surface area of the two- and three-patches configuration was the same (10 cm2 vs 9.9 cm2). Epicardial spatial configuration was planned by using a computerized heart model. In ten anesthetized open-chest pigs, ventricular fibrillation was induced by using AC current through the mesh plaque epicardial custom-designed electrodes, and the minimum energy requirement for defibrillation was determined 15 seconds after the onset of stable ventricular fibrillation. Results were as follows (mean +/- standard deviation): Defibrillation Threshold 16 +/- 9 J 9 +/- 5 J P less than 0.01 CONCLUSIONS: three epicardial patches configuration significantly reduces energy requirements for defibrillation compared with two patches when single pulse shock is used.

Animals↗
PubMed1991

[Right accessory pathway simulating a nodo-ventricular pathway: an electrophysiologic study and intraoperative mapping].

We report a case of a patient with episodes of wide QRS tachycardia and syncope. During the electrophysiologic study, a wide QRS tachycardia (200 b/m) with left bundle branch block morphology was reproducibly induced by incremental atrial pacing with progressive shortening of the HV interval and lengthening of the AV interval, suggesting the presence of a nodoventricular accessory pathway (Mahaim fiber). The intraoperative mapping performed during tachycardia showed the earliest ventricular activation to be over the right antero-lateral AV groove, different from the usual epicardial activation previously described. According to the earliest epicardial breakthrough point, we performed an epicardial AV fat pad dissection which produced irreversible disappearance of preexcitation, confirmed at the postoperative electrophysiologic study. No recurrence of tachycardia was observed during a follow-up of 11 months. This case further confirms previous data that the "so-called" Mahaim fibers could be a right accessory pathway with decremental properties.

Adult↗
PubMed1990

[Aortic valve replacement in a case of Takayasu's disease with polydistributed localization].

We report a case of a 49 year-old woman suffering from severe aortic regurgitation due to Takayasu's disease involving the ascending and abdominal aorta and the brachial arteries. The patient was managed successfully with aortic valve replacement. Considering the Literature data, the pathogenesis of the aortic insufficiency and the main surgical and anaesthesiologic problems related to the Takayasu's disease are discussed.

Adult↗
PubMed1990

Opposite effects of propafenone and flecainide in a patient with reciprocating supraventricular tachycardia.

A 46 year-old woman with Wolff-Parkinson-White syndrome (postero-septal accessory pathway), symptomatic for recurrent episodes of nonsustained paroxismal supraventricular tachycardia (PSVT), was empirically treated with propafenone (600 mg/day). After a week of therapy the patient returned to the hospital after an episode of syncope. She referred a significant increase in duration and frequency of "palpitations". Under treatment with propafenone a sustained PSVT could be induced during transesophageal testing. During the electrophysiologic study performed off drugs, only a nonsustained PSVT could be induced. After flecainide infusion (1 mg/kg) anterograde block of the accessory pathway was observed and only few beats (less than 8) of PSVT could be induced. The patient was discharged on flecainide (200 mg/day) and 1 month later a transesophageal testing was repeated showing an anterograde block of the accessory pathway at a pacing cycle length of 500 ms; no arrhythmias were induced. The patient has been asymptomatic on chronic oral therapy with flecainide during a follow-up period of 8 months. This case shows that 2 1c class antiarrhythmic drugs may have opposite effects (proarrhythmic and antiarrhythmic). Failure, or even the proarrhythmic effect of one drug, does not necessarily exclude the efficacy of another drug of the same subclass in preventing recurrence of PSVT.

Administration, Oral↗
PubMed1990

Intravenous propafenone reduces energy requirements for defibrillation in pigs.

The effect of antiarrhythmic drugs on defibrillation threshold have become an important issue with the increasing use of the automatic implantable cardioverter defibrillator (AICD). In several reports antiarrhythmic therapy has been found to affect the energy required for defibrillation; the present study examined the effects of intravenous propafenone on defibrillation threshold in open chest, anesthetized pigs. Twenty health pigs were studied; 10 pigs free from any drugs (Group 1) and 10 pigs after a constant iv infusion of 0.04 mg/kg/min of propafenone (Group 2). Defibrillation threshold was 21 +/- 5, 20 +/- 5, 21 +/- 6, 19 +/- 4 and 19 +/- 6 J in Group 1 and 20 +/- 7, 18 +/- 9, 15 +/- 5, 14 +/- 7, 9 +/- 6 J in Group 2, respectively at 20, 40, 60, 80 min (p value respectively NS, NS, less than 0.05, less than 0.01, less than 0.001). We conclude that intravenous propafenone reduces the energy requirements for defibrillation in experimental animals.

Animals↗
PubMed1990

[Infectious endocarditis. Role of surgical therapy].

The problem of infectious endocarditis (IE) is approached through a review of personal experience. The series examined consists of patients, 17 with active and 21 dormant infection. Furthermore 12 in the first group, 18 in the second had natural heart valves, while 5 in group I, 3 in group II had been given artificial ones. After an analysis of the aetiopathogenic, clinical and diagnostic aspects of the condition with emphasis on the fact that Staphylococcus aureus is currently more responsible for infections in natural valves and the epidermidis for acute prosthesis infections which have a higher early and late mortality rate (40% in hospital, 33.3% long-term), the paper discusses the criteria for surgical intervention. In line with opinions expressed in the literature, it is pointed out that, while the patient's haemodynamic status is certainly the main criterion for any decision, other factors such as embolism, impaired conduction, kidney failure and expansion of the infection to contiguous tissues, should not be under-estimated.

Endocarditis, Bacterial↗
PubMed1990

[What is the best treatment in massive pulmonary embolism: anticoagulants, thrombolytics or surgical embolectomy?].

The aim of this work was to identify the best treatment available for massive pulmonary thromboembolism which still remains a frequent and sometimes lethal complication for surgical and non-surgical patients. The Authors underline the difficulties of diagnosis and the need for therapy at the earliest possible stage. At present, clinical management involves the use of: anticoagulants, thrombolytic agents and surgical embolectomy. In conclusion, the authors state that pulmonary thromboembolism, even when massive, has been transformed into a medically interesting pathology which can be cured using heparin and thrombolytic agents. However, surgical treatment is mandatory when patients reveal adverse effects to drug therapy, when medical therapy is insuccessful, or when patients are seriously ill with recurrent cardiac arrest.

Anticoagulants↗
PubMed1989

[Bidirectional tachycardia during therapy with lorajmine].

We report a case of bidirectional tachycardia (BT) found on Holter recording (H-ECG), likely due to antiarrhythmic therapy with lorajmine. The patient, who was not on digitalis therapy and had good myocardial function, was investigated for presyncope. H-ECG revealed frequent premature ventricular complexes (PVC). Disopyramide, lorajmine and amiodarone (in succession) were ineffective in controlling the arrhythmias. During therapy with lorajmine (600 mg/die) H-ECG showed numerous symptomless episodes of BT. Two forms of BT were found. In the first one the PVC had a right bundle branch block (BBB) pattern in lead CM1 and alternating polarity (Rs-rS) in lead CM5, whereas in the second one an alternating right and left BBB pattern in CM1 was found. PVC were subsequently controlled with flecainide. In a 4-year follow-up period the patient underwent several H-ECGs, both with and without antiarrhythmic drugs; however, BT episodes were found only during lorajmine therapy. Thus, this drug was likely responsible for the appearance of BT episodes.

Aged↗
PubMed1989

[Blood platelet count and bubble oxygenators. Changes induced by the oral administration of dipyridamole].

The changes in thrombocythemia in patients subjected to extracorporeal circulation (ECC) and pretreated with dipyridamole per os have been examined and compared with a control group in whom the drug was not used; in all patients a circuit with bubble oxygenator was employed. Measurements were carried out before sternotomy, 10' and 60' after ECG, 1 h after the start of intensive therapy and on the 1st surgical day. The variations in thrombocythemia were assessed in consideration of the thrombocythemia/Ht ratio, so as to eliminate the dilution variable. On the basis of the results obtained, it is considered that preoperative treatment with dipyridamole is effective in limiting the fall in thrombocythemia during ECC. The effect of the drug is prevalent in the initial stage of ECC, probably reducing platelet aggregation to non-biological surfaces of the circuit.

Administration, Oral↗
PubMed1989

[Reversibility of left ventricular functional damage after valve replacement in patients with chronic aortic valve insufficiency].

The authors study retrospectively some preoperative echocardiographic findings and their importance as predictors of reversible myocardial dysfunction. The functional status of 57 survivors after isolated aortic valve replacement was evaluated with exercise testing and on this ground the patients, were divided into three groups: A (28 pts) greater than 60%; C (10 pts) less than 40%; B (19 pts) from 40% to 60%. The authors conclude that the postoperative improvement in functional status is strictly correlated with some preoperative echocardiographic indexes (end-diastolic dimension, end-systolic dimension, shortening fraction, mean end-systolic radius/thickness ratio, end-systolic wall stress, myocardial mass, ejection fraction) with are also predictive of operative mortality. The authors consider the principal values of beginning left ventricular impairment: a) end-systolic dimension greater than or equal to 5.5 cm; b) shortening fraction less than 27%; c) mean end-systolic radius/thickness ratio greater than 2.5; d) end-systolic wall stress greater than 240 mmHg.

Aortic Valve Insufficiency↗
PubMed1987

Prevalence of late potentials in patients undergoing Holter monitoring.

UNLABELLED: High-frequency, low-amplitude signals detected in the terminal portion of the surface QRS, called late potentials (LP), have been shown to correlate with inducible sustained ventricular tachycardia and to be absent in normal subjects. We studied LP in 152 patients without a history of sustained ventricular tachycardia who underwent 24-hour Holter monitoring for varying clinical indications (chest pain 21%, syncope 17%, palpitations 32%, dizziness 20%, other 10%). Twenty-one patients (14%) had a positive test. Of the 152 patients, 84 (55%) had complex ventricular arrhythmias and 68 (45%) had simple or no ventricular arrhythmias. Complex ventricular arrhythmias were present in 71% of patients with and in 52% of those without LP. IN CONCLUSION: patients without history of sustained ventricular tachycardia who demonstrate complex nonsustained ventricular arrhythmias on Holter monitoring have a low prevalence of LP; the presence of LP on signal-averaged ECG indicates an electrical property of the heart, which is distinct from complex ventricular arrhythmias detected on Holter monitoring.

Arrhythmias, Cardiac↗