Aerobic exercise and Orexin A: role of sympathetic activity and redox system.

Aerobic exercise is associated with the sympathetic activation evoking adaptive responses to sustain muscle engagement. Physical exercise can cause alterations in the cardiovascular activity and cellular stress may occur which could be marked by either heart rate (HR), or galvanic skin response (GSR). Moderate plasma levels of reactive oxygen species (ROS) are considered as health markers, absolving to important roles such as adaptive cellular responses to exercise. Orexin A, a hypothalamic peptide, causes a widespread stimulation of the sympathetic nervous system, playing a role in many physiological functions.

Excimer laser technology in percutaneous coronary interventions: Cardiovascular laser society's position paper.

Excimer Laser Coronary Atherectomy (ELCA) is a well-established therapy that emerged for the treatment of peripheral vascular atherosclerosis in the late 1980s, at a time when catheters and materials were rudimentary and associated with the most serious complications. Refinements in catheter technology and the introduction of improved laser techniques have led to their effective use for the treatment of a wide spectrum of complex coronary lesions, such as thrombotic lesions, severe calcific lesions, non-crossable or non-expandable lesions, chronic occlusions, and stent under-expansion. The gradual introduction of high-energy strategies combined with the contrast infusion technique has enabled us to treat an increasing number of complex cases with a low rate of periprocedural complications. Currently, the use of the ELCA has also been demonstrated to be effective in acute coronary syndrome (ACS), especially in the context of large thrombotic lesions.

Anatomic and electrophysiologic substrate of the permanent form of junctional reciprocating tachycardia.

Data are reported on three patients with the permanent form of junctional reciprocating tachycardia, in whom conduction over a slow accessory pathway was observed after His bundle ablation. Tachycardia was almost incessant and showed a retrograde P wave (P') and RP' interval longer than P'R interval in all patients; during sinus rhythm, the PR interval was normal and there was no evidence of a delta wave. An accessory pathway with a long conduction time located in the posterior pyramidal space provided the retrograde limb of the reentry circuit. After His bundle ablation, the accessory pathway was capable of conducting in both anterograde and retrograde directions with decremental properties in all patients. Postmortem documentation of the accessory pathway was achieved in one patient. Serial sections revealed an accessory atrioventricular connection composed of ordinary myocardium joining the lower rim of the coronary sinus outlet to the uppermost ventricular muscle. This anomalous atrioventricular connection pursued a sinuous, tortuous path. As a result of changing cross-sectional area, such an accessory pathway might exhibit slow conduction, thus explaining its decremental characteristics.

Transesophageal pacing for prognostic evaluation of preexcitation syndrome and assessment of protective therapy.

An esophageal lead was used to perform decremental atrial pacing and elective induction of atrial fibrillation (AF) in 5 patients with the Wolff-Parkinson-White (W-P-W) syndrome before and after amiodarone therapy. In the control state, 1:1 atrioventricular (AV) conduction over the accessory pathway ranged from 220 to 260 ms (mean 232). The shortest R-R interval during AF ranged from 190 to 210 ms (mean 198). The ventricular rate ranged from 175 to 212 beats/min (mean 196). After amiodarone therapy, the shortest cycle length with 1:1 AV conduction increased in all patients, ranging from 290 to 540 ms (mean 370); during AF, no preexcited beat was present in 2 patients, whereas the minimal preexcited R-R interval in the remaining 3 was 290, 240, and 370 ms, respectively. The ventricular response during AF decreased in all patients. Thus, esophageal pacing is a useful method for identifying patients at risk with the W-P-W syndrome and for assessing appropriate management in individual patients. Amiodarone provides protection against life-threatening arrhythmias in these patients.

Catheter ablation of accessory pathway in the permanent form of junctional reciprocating tachycardia.

Successful transvenous catheter ablation of accessory pathway (AP) in a patient (pt) with the permanent form of junctional reciprocating tachycardia is reported. A concealed AP with long conduction time comprised the retrograde limb of tachycardia circuit. The atrial end of the AP was near the coronary sinus (CS) orifice. Catheter ablative technique was performed after assessment of its feasibility and safety by using a canine model. During an electrophysiologic study CS mapping was obtained; the earliest retrograde activity was recorded 1-2 cm inside the orifice of the CS. Two unipolar shocks of 120 J were delivered on the sites exhibiting the earliest retrograde atrial activity. After the procedure, the AP was no longer conducting in both anterograde and retrograde direction. During a follow-up period of 13 months, the pt remained free of tachycardia on no antiarrhythmic medication.

Reduction of coronary flow reserve non-invasively determined by transthoracic Doppler echocardiography as a predictor of left anterior descending coronary artery stenosis.

BACKGROUND: The aim of this study was to evaluate if a reduced coronary flow reserve determined by transthoracic echocardiography alone or combined with contrast agents may represent a predictive index of significant left anterior descending coronary artery (LAD) stenosis. METHODS: Thirty-four patients (mean age 59+/-9 years) undergoing coronary angiography for coronary artery disease were studied. Coronary stenosis was classified (according to visually determined percent narrowing) as severe (> 75%), moderate (40 to 75%) and mild (< 40%). Coronary blood flow velocities were recorded in each patient at baseline and after low-dose dipyridamole administration by use of a 3.5 MHz transducer with a machine equipped with second harmonic capability and nondirectional color Doppler software. Coronary flow reserve was defined as the ratio of hyperemic to basal diastolic peak velocity. RESULTS: Adequate Doppler recordings in the LAD were obtained by transthoracic echocardiography in 26/34 patients (76%); the infusion of Levovist allowed for the visualization of LAD flow in a further 7 patients, with an overall feasibility of 97%. Coronary flow reserve was significantly higher in the group of patients with mild coronary lesions (2.3+/-0.3) than in patients with moderate (1.68+/-0.29, p = 0.0004) or severe (1.49+/-0.39, p = 0.0005) LAD stenosis. CONCLUSIONS: By use of transthoracic echocardiography combined with contrast agents it is possible to visualize blood flow velocities in the LAD and to evaluate coronary flow reserve after dipyridamole infusion with a non-invasive approach. Combined with angiographic findings, this diagnostic approach could be useful in giving additional information to assess the functional significance of a stenotic coronary lesion.

Disulfiram neuropathy: a review (1971-1988) and report of a case.

Neuropathy is one of the most severe side effects of disulfiram therapy. We report the case of a young man who developed a neuropathy following disulfiram administration, with a virtually complete recovery in 14 months. We then discuss 37 cases of disulfiram neuropathy reported since 1971. Evidence is given that: (1) there is no numerical sex prevalence, although the incidence of the disease in women is probably disproportionately high; (2) symptom onset latency is dose-dependent, being longer at 250 mg/day or less; (3) neurological deficits are also dose-dependent, being milder at 250 mg/day or less; (4) the two previous findings and single observations suggest that disulfiram neuropathy is a dose-dependent phenomenon; (5) recovery probably follows a course which depends primarily on the initial degree of impairment; (6) the genetic mechanism probably involves carbon disulfide and a hypothesis as to the possible biochemical mechanism is proposed; (7) chloral hydrate can bear a potentiation effect on neuropathy, and the association with disulfiram is best avoided. Further, we give guidelines for the differentiation between alcoholic and disulfiram neuropathy, advise prescribing the drug at 250 mg daily or less, if possible, and stress the utmost importance of an early diagnosis.