Archivos del Instituto de Cardiologia de Mexico最新文献

Isolated congenital atrioventricular block is reported in one out of 20,000 live births. The optimistic view on the prognosis and indications for permanent pacing have been modified in the last 35 years. The purpose of this report is to present a prenatally diagnosed case, outlining the surgical technique for permanent pacing. The infant was a male born by cesarean section, weighted 3030 grs and had a structurally normal heart. His ECG showed complete AV block with narrow QRS, atrial rate was 140 and ventricular rate was 55. We implanted a epicardial pacemaker VVIR by midline laparatomy. The lead was unipolar 35 cms long screw-in type and was placed in the right ventricle through the xiphoid process. The pacemaker was placed in a GoreTex bag and fixed intraperitoneal to the abdominal wall. The infant did well after the procedure and he was discharged in good condition one week later. We conclude that it is appropriate to implant a permanent pacemaker in these patients with low ventricular rate thus reducing the risk of sudden cardiac death. The surgical technique is safe and makes easy the generator replacement.

The enzymatic activity of the mitochondrial oligomycin-sensitive ATPase was investigated during isoproterenol-induced cell injury of myocardium, using rat heart homogenates and a potentiometric method. The enzymatic activity of the oligomycin-sensitive ATPase and the inhibitory action of oligomycin do not show significant alterations upon treatment with isoproterenol. These results are inconsistent with the hypothesis that modifications in the active configuration of the mitochondrial ATPase take place during isoproterenol-induced injury of myocardium.

The efficacy and safety of intravenous propafenone for conversion of recent-onset and chronic atrial fibrillation was assessed in 46 patients. 40 with atrial fibrillation associated with or without structural heart disease (mean age 63 +/- 14 years) and 6 patients with atrial fibrillation related to the Wolff-Parkinson-White syndrome (mean age 34.8 +/- 13 years). Propafenone treatment was administered at 2 mg/kg over 15 minutes under continuous electrocardiographic monitoring. In 28 of 32 (87.5%) patients with paroxysmal and/or recent-onset atrial fibrillation a stable sinus rhythm was restored within 1 hour after propafenone (mean 17 +/- 11 minutes) and in only 3 of 8 (37.5%) with chronic atrial fibrillation (p < 0.05). Conversion to sinus rhythm was obtained in 5 of 6 (83.3%) patients with atrial fibrillation related ventricular preexcitation, mean time 21 +/- 12 minutes. Propafenone had an additional effect reducing mean heart rate (141 +/- 21 to 102 +/- 15 beat per minute, p < 0.05) and the shortest preexcited R-R intervals was increased, mean 231.6 +/- 27.8 to 355 +/- 37.2 milliseconds (p < 0.001) in cases associated with ventricular preexcitation. Dizziness, hypotension and transient conduction disturbances occurred in only one patient with rheumatic valvular heart disease: EF 40%. Propafenone is an effective and safe antiarrhythmic drug for converting paroxysmal and/or recent-onset atrial fibrillation of various origins with a more limited efficacy in chronic atrial fibrillation.

Up to 1982, surgery was the treatment of aortic coarctation, with postsurgical recoarctation in 39% of cases. Since 1984 balloon aortoplasty has been performed successfully in adolescents and adult patients. We present the immediate results, and more than six months follow up of 6 patients with congenital aortic coarctation, who underwent this procedure. Five of the six patients were male, with an average age of 28.6 years (15-46), and in 4 of them a stent was placed. Systolic pressure of ascending aorta decreased from 187.1 mm of Hg (+/- 41.8) to 128 (+/- 25.4), and transaortic gradient from 66 mm of Hg (+/- 21.8) to 4.8 (+/- 7.6). Coarctation luminal diameter increased from 4.6 mm (+/- 1.41) to 14.3 (+/- 3) in patients with only balloon aortoplasty and to 17.8 mm with stent placement, p = NS. Angiography in three patients with stent at 6 months did not reveal restenosis, all six patients require less antihypertensive medications. Acute and chronic complications, percentage and time of restenosis, long term results, and possible benefit of stents are yet to be determined.

This is the case of a 27 years-old woman with signs and symptoms of severe untreatable congestive heart failure, anemia, gingival mucosa ulcers, photosensitivity and alopecia. The electrocardiographic, echocardiographic, angiographic and hemodynamic data oriented the diagnosis of restrictive cardiomyopathy, mitral insufficiency secondary to mitral prolapse and bi-atrial dilation. The histologic study of the endomyocardial biopsy, performed during catheterization, showed signs of endomyocardial fibrosis, and immunological analysis was compatible with systemic lupus erythematosus. As far as we know, this is the first case of endomyocardial fibrosis (Davies disease) associated with systemic lupus erythematosus published in the medical literature. The etiology of Davies disease remains unrevealed and its association with systemic lupus erythematosus suggest a probable autoimmune origin.

Background: The purpose of this study was to examine the spontaneous changes in cycle length during episodes of sustained monomorphic (MVT) and polymorphic (PVT) ventricular tachycardias and to relate these changes with the earliest epicardial activation site of the beat.

Methods: Isochronal activation maps were obtained from 127 unipolar electrograms recorded from the surface of both ventricles with a sock electrode array in 24 open chest anesthetized dogs. After atrioventricular block, the left anterior descending coronary artery was occluded for 60 min under ventricular pacing (140/min), followed by reperfusion. In 7 dogs the left stellate ganglion was stimulated 5 min after reperfusion.

Results: In 7 MVTs (reperfusion) and 4 PVTs (sympathetic stimulation), cycle length changes showed an initial acceleration, reaching a minimum cycle length and then decelerating before termination. Isochronal maps showed radial spread from earliest activation, without conduction block. Cycle length (481 +/- 80 msec) in MVT had beat to beat variations of 15 +/- 17 msec corresponding to small shifts in sites of the earliest activation, clustered along the border of the ischemic myocardium. In PVTs the cycle length (352 +/- 90 msec, p < 0.01) had a variability of 62 +/- 23 msec, corresponding to wide changes in the sites of earliest activation in right and left ventricles. Linear regression analysis showed a strong and significant correlation between cycle length variability and the number of electrodes with the earliest activation (r = 0.77, p < 0.0001).

Conclusion: In these models of monomorphic and polymorphic ventricular tachycardias, cycle length variability showed a significant correlation with the number of electrodes with the earliest activation. MVTs showed concentrated origins with regular cycle length, whereas PVTs showed dispersed origins with irregular cycle length. These results suggest that the earliest epicardial activation site of the beat could be a factor in determining the dynamics in the cycle length.

Atrial septal defect (ASD) represents a congenital heart disease with good prognosis, however, atrial arrhythmias are well-documented complications. A retrospective study was performed to assess the prevalence, types and risk factors of arrhythmias in patients with ASD after surgical correction. 920 patients were analyzed retrospectively; cases with complex congenital heart disease or another systemic alteration conditioning atrial rhythm disturbances were excluded. 460 patients with ASD corrected by surgery were followed at least for six months after the procedure. 29.3% of patients were male and 70.7% female. Direct closure was performed in 63%, pericardial patch was installed in 27%. 29 patients (6.3%) had conduction and rhythm disturbances before surgery, the most common arrhythmias were atrial flutter (34.5%), first degree A-V block (31%) and low right atrial rhythm (27.6%). Six months after atrial defect closure, 65 patients (14.13%) had arrhythmias, 44.6% atrial flutter, 20% ectopic atrial rhythm, 10.8% sick sinus syndrome. The risk of atrial arrhythmias was related to age at surgical repair, pulmonary hypertension and atrial arrhythmias before surgery.

We review the literature on heart wounds. Along the history surgeons regarded heart wounds as forbidden place for therapeutic approach. We present a patient who sustained a bullet wound to the heart and two years later 3 knife' stabs in the same place injuring its 4 valves and inducing 2 fistulae: one from the aorta to the pulmonary artery, the other from left-ventricle and the pulmonary artery. Surgery was successful in repairing the damage without the need of valve replacement.