Percutaneous angioscopy in patients with restenosis after excimer laser coronary angioplasty.

Coronary angioscopy was performed in two patients with restenosis after excimer laser coronary angioplasty to improve our knowledge of restenosis after excimer laser angioplasty. The characteristics of the angioscopic findings in restenosis after excimer laser angioplasty consisted of smooth white plaques, which were distinctly different from the yellow plaques commonly observed in primary lesions. These findings indicate that restenosis in these patients after excimer laser angioplasty may be associated with smooth muscle cell proliferation and fibrosis.

External vibration interference of activity based rate responsive pacemakers.

The change of the pacing rate in response to external vibration interference was assessed in four rate responsive pacemakers with a piezoelectric crystal (Medtronic Activitrax 8403, Siemens Sensolog 3, Biotronik Ergos 01, and Medtronic Legend 8417) and one with an accelerometer (CPI Excel VR 1119). They were tested in the laboratory. External vibration was simulated in vitro by exposing the different pacemakers to a controlled sinusoidal vibration force generated by a Millar pressure vibration amplifier type MGM-30 (Millar Instruments, Inc., Houston, TX, USA). All pacemakers were programmed at standard settings. Two types of vibration forces were applied: (1) one with varying amplitude but with constant vibration frequency; and (2) one with varying frequency but with constant vibration amplitude. In this manner curves of pacing rate versus vibration forces versus vibration frequency were obtained. High vibration forces and low vibration frequencies were associated with the highest pacing rate response. In this experimental setting, the pacemaker based on the accelerometer principle apparently was the least sensitive to high frequency vibrations, which are known to be related to environmental interference. It also seemed more appropriately responsive in the lower frequency range, which is more appropriate for the detection of true physiological activity.

Predictive value of the P wave at implantation for atrial fibrillation after VVI pacemaker implantation.

This study assesses the value of P wave measurements on the surface ECG at implantation, in the prediction of atrial fibrillation in VVI paced patients. From a consecutive series of 320 pacemaker implantations 172 VVI paced patients for symptomatic atrioventricular block (AVB) (n = 126; mean age 69 +/- 14) or sick sinus syndrome (SSS) (n = 56; mean age 68.6 +/- 12) and in sinus rhythm at implantation were used in this study. P wave duration in V1 is correlated with the incidence of atrial fibrillation during 5 years of follow-up. V1 at implantation was significantly longer (114.6 +/- 2.7 msec) in the patients who developed atrial fibrillation than in those who did not (91.9 +/- 2.7 msec) (P < 0.001). Although positive predictive accuracy increases progressively for higher V1 values for AVB and SSS, the negative predictive and diagnostic accuracy of V1 criteria were less in SSS. Application of the Bayes' theorem showed that in SSS the probability to develop atrial fibrillation is 33% for V1 < 110 msec and is for V1 < 90 msec still higher than that reported in DDD paced patients. In the AVB group the probability to develop atrial fibrillation is 8% for V1 < 110 msec and 6% for V1 < 100 msec. It seems, therefore, that atrial stimulation (AAI or DDD) is always indicated in SSS. In AVB with V1 < 100 msec, DDD pacing, if not needed for other indications, apparently does not offer much benefit in the prophylaxis of atrial fibrillation.

Aneurysmal formation after successful pulsed laser coronary angioplasty.

We report two cases of coronary artery aneurysmal formation as long term consequences of Ho:YAG and excimer laser coronary angioplasty. This case report suggests that pulsed laser angioplasty may result in severe vessel wall damage that may lead ultimately to aneurysmal formation.

[P wave changes and atrial fibrillation after implantation of VVI type pacemaker]. / Modifications de l'onde P et fibrillation auriculaire après l'implantation d'un pacemaker type VVI.

The P waves of patients with VVI pacemakers were compared with those of DDD pacemakers at implantation and then regularly for 5 years. A certain number of cardiac pathologies are known to cause P wave changes. The incidence of atrial fibrillation (AF) was much higher in VVI than in DDD patients. In the VVI group, the incidence was much greater in patients paced for sinus node disease than in patients paced for AVB. Analysis of sinus P wave characteristics in 320 patients with VVI pacemakers shows progressive abnormalities of atrial function with time. The expression of this atrial dysfunction is a statistically significant prolongation of the P wave in V1 and dII and of the terminal part of the P wave in V1. The factors responsible for this abnormality and which favours the occurrence of AF are quasi-permanent pacing, the presence of retrograde conduction and an abnormality of atrial activation at the time of implantation.

Capnocytophaga canimorsus endocarditis.

We report a case of aortic valve endocarditis, caused by Capnocytophaga canimorsus (previously known as CDC Group DF-2) secondary to a dog bite. Vegetations were documented by cross-sectional echocardiography and bacteraemia by positive haemocultures for this unusual gram-negative bacillus.

Pneumoperitoneum--a rare complication of cardiopulmonary resuscitation.

Pneumoperitoneum following cardiopulmonary resuscitation (CPR) results from a thoracic air leak (pneumothorax, pneumomediastinum) with escape of the air through diaphragmatic apertures (mostly foramen of Winslow) or primary perforation of the gastrointestinal tract (stomach or esophagus). We report three cases of pneumoperitoneum complicating CPR. As there was no clinical evidence of peritonitis, and the patients remained stable, a conservative approach was followed without surgical exploration. All patients recovered completely.

Evolution of P wave characteristics after pacemaker implantation.

This study is an investigation of the long-term effects of VVI pacing on the atrium as derived from the evolution of P wave characteristics of 285 patients. The occurrence of left and right atrial disease is demonstrated as well as the evolution of left atrial hypertrophy in some cases. A comparison is made with DDD pacing and special attention is given to the progression to atrial fibrillation.

[Malignant pheochromocytomas. Apropos of a case with multiple metastatic localizations]. / Les phéochromocytomes malins. A propos d'un cas avec localisation métastatique multiple.

We are reporting a case of malignant pheochromocytoma surgically treated initially for an isolated left pararenal localization, and which recurred several years later accompanied with numerous metastases. Despite of a treatment with Iodine 131 MIBG, the evolution was rapidly fatal with a picture of cardiac failure. This cardiac involvement would be linked to a myocarditis directly secondary to the catecholamines and causing a marked increase of the free fatty acids concentration in the heart tissue. In reference to this case, all the data which may tend to suspect the malignant nature of a pheochromocytoma, present in 10 p. cent of the cases, are successively reviewed. There is no clinical specificity. The presence of a mixed secretion with marked urinary dopamine secretion, would not present, for all authors, the same criteria of specificity. Thoraco-abdominal scan and scintigraphy with iodine 131 MIBG are the two tests permitting to demonstrate, with a great sensitivity and specificity, an extra-adrenal localization, which is the best argument in favor of a malignancy since 30 to 40 p. cent of extra-adrenal pheochromocytomas are malignant, more especially as the metastases are located in areas where there are no embryonic remnants of tissues containing chromaffin cells. This permits to appreciate the difference between a non-malignant multicentric pheochromocytoma and a malignant pheochromocytoma. The ideal treatment of a malignant pheochromocytoma rests on surgery under the condition that there are ony one or two metastases. This procedure is preceded by a sodium nitroprusside preparation and followed with an alpha-blockers treatment. In case of multiple metastases, the therapeutic use of iodine 131 MIBG seems to be a tempting alternative.