PubMed Health⌕ Search

Biomedical subjects

J M Barbero

Publications and source records attributed to J M Barbero.

5 recordsLinked to original sources

[Exercise-induced atrioventricular block].

Exercise-induced atrioventricular block in patients with normal atrioventricular conduction at rest is uncommon. Electrophysiologic studies have documented block distal to the atrioventricular node in these patients. Implantation of a permanent pacemaker is recommended because of a high incidence of subsequent symptomatic block. We report three symptomatic patients with exercise-induced atrioventricular block. Two patients showed a bundle branch block in the baseline electrocardiogram, suggesting a distal location of the block. In the remainder, with a normal QRS, the electrophysiologic study revealed AV block within the His bundle in response to atrial pacing.

Aged↗

Intracardiac coiling of permanent atrial leads.

We have observed intracardiac movement of permanently implanted atrial pacing leads in two patients with AAI pacemakers. This resulted in looping of the lead body into the right atrium and ventricle, without displacement of the tip or changes in the pacing or sensing thresholds. At surgery only a single fixation ligature was found and allowed sliding of the lead through the suture sheath, in both cases. The position was corrected by gently pulling the lead. Multiple ligature fixation may avoid this complication.

Aged↗

[Post-infarction thrombosis of the right ventricle].

Right ventricular mural thrombosis is not commonly detected and in most cases is related to the use of monitoring, infusion, or pacing catheters. We report right ventricular mural thrombosis, complicated by pulmonary embolism, in 2 cases of inferior wall myocardial infarction with right ventricular involvement. None of the patients had been monitored by means of right ventricular catheterization. Bidimensional echocardiography allowed visualization of the thrombi, and demonstrated their resolution after anticoagulant treatment.

Aged↗

Validation of double-spike electrograms as markers of conduction delay or block in atrial flutter.

Recent mapping studies of atrial flutter have shown that fragmented electrograms can be found in most cases from the posterior, posteroseptal and posterolateral walls of the right atrium. The fragmentation pattern most often consists of a double spike. To further assess double-spike electrograms as a possible marker of conduction delay, bipolar electrograms were continuously recorded during atrial overdrive pacing of common flutter from the right atrium (7 patients) and from the proximal coronary sinus (5). Baseline double-spike separation of 50 to 130 ms was unchanged in 1 patient and slightly increased (5 to 25 ms) in 4 by coronary sinus pacing. The electrogram sequence was unchanged and the surface morphology was similar to that of basal flutter. Right atrial pacing decreased double-spike separation by 25 to 85 ms from basal values of 45 to 175 ms (23 to 83%), suggesting fusion in the area of fragmented electrograms. These findings suggest that double-spike electrograms represent activation on both sides of a conduction delay zone. The changes induced in these electrograms by pacing from the anterior right atrium and the coronary sinus are consistent with flutter circuits rotating counterclockwise (frontal plane) in the posterior right atrial wall in common atrial flutter.

Atrial Flutter↗

[Severe hypoxemia due to a right-left shunt at the level of the foramen ovale. A complication of right ventricular infarct].

A 76-year-old woman with an inferior wall myocardial infarction, with right ventricular involvement, developed severe arterial hypoxemia with neurological involvement. Pulmonary edema or embolism and chronic obstructive pulmonary disease were ruled-out, and a right-to-left shunt was demonstrated by contrast echocardiography at the level of the foramen ovale. After inotropic support and oxygen supplementation, the patient recovered, although with significant neurological sequelae. No focal lesions were detected in the central nervous system by computerized tomography. Hypoxemia improved, coinciding with the disappearance of right-to-left shunt by contrast echocardiography.

Aged↗