Paraseptal accessory connections in the proximity of the atrioventricular node and the His bundle. Additional observations in relation to the ablation technique in a high risk area.

INTRODUCTION: Paraseptal pathways, namely, accessory connections (AC) in the vicinity of the atrioventricular node (AVN) and the bundle of His, are associated with a high risk of complete atrioventricular block (AVB) during transcatheter radiofrequency ablation (RFA) in the Electrophysiology Laboratory. In previously reported series of ablation of paraseptal ACs, the coexistence of multiple ACs in this high-risk region has rarely been mentioned. METHODS AND RESULTS: We studied 15 patients undergoing RFA of paraseptal ACs 2 of whom had dual pathways with an additional midseptal pathway revealed after the elimination of the anteroseptal target AC. The fundamental goal of the pre-ablation electrophysiological mapping was the clear-cut determination of anatomical site with His bundle recording activity. This required unique pharmacological and programmed electrical stimulation manipulations in 8 patients in whom His bundle recording activity was only temporarily possible. After identifying the corresponding His bundle site, special attention was given to the ablation catheter being situated at least 3 mm away, thus recording minimal or no His bundle activity. Additional precautions were taken so that the delivered therapy was of minimal duration and powered by temperature regulation with immediate interruption in case of AVB or nodal rhythm appearance. With this therapeutic approach, 16 of the 17 paraseptal ACs were ablated successfully with the inadvertent induction of AVB in only 1 patient. In the patient with persistent ventricular preexcitation after the ablation session, modification of both the AC and the AVN was noted so that the previously easily induced reciprocating atrioventricular tachycardia was no longer so, using programmed stimulation. CONCLUSION: Transcatheter radiofrequency ablation is a feasible and effective radical therapy for patients with paraseptal ACs, provided the His bundle site has first been clearly defined and the coexistence of other nearby tracts has been excluded.

The J-shaped effect of coffee consumption on the risk of developing acute coronary syndromes: the CARDIO2000 case-control study.

The effect of coffee consumption on cardiovascular disease has been debated for many years. In this work, we evaluated the association between coffee consumption and the risk of developing acute coronary syndromes, based on a random sample of 848 patients with their first coronary heart disease event and 1078 frequency-matched controls with no cardiovascular disease in their medical history, from the entire country. The multivariate analysis raises a J-shaped association between the risk of developing acute coronary syndromes and the quantity of coffee consumed per day. In particular, the odds ratios for moderate (<300 mL/d), heavy (300-600 mL/d), and very heavy (>600 mL/d), consumption, relative to no consumption, were 0.69 (95% CI, 0.50-0.86), 1.56 (95% CI, 1.10-2.34) and 3.10 (95% CI, 1.82-5.26), respectively, after controlling for the presence of hypertension, hypercholesterolemia, diabetes mellitus, family history of premature coronary heart disease, physical activity status, smoking habits, BMI, alcohol consumption, triglycerides, consumption of several food items, depression scale score and education status. The suggested J-shaped association between coffee consumption and the risk of developing acute coronary syndromes may partially explain the conflicting results from other studies in the past.

Effects of antioxidant vitamins C and E on endothelial function and thrombosis/fibrinolysis system in smokers.

Smoking is associated with endothelial dysfunction and abnormalities in thrombosis/fibrinolysis system, possibly through increased oxidative stress. In this study we investigated the effect of combined antioxidant treatment with vitamins C and E on endothelial function and plasma levels of plasminogen activator inhibitor (PAI-1), von Willebrand factor (vWF), tissue plasminogen activator (tPA) and factor VII (fVII), in smokers. Forty-one healthy smokers were randomly divided into 4 groups receiving vitamin C 2g/day (group A), vitamin C 2g/day plus vitamin E 400 IU/day (group B), vitamin C 2g/day plus vitamin E 800 IU/day (group C) or no antioxidants (controls, group D), for 4 weeks. Forearm blood flow was measured using venous occlusion strain-gauge plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) or to sublingual nitroglycerin administration (NTG%) were considered as indexes of endothelium dependent or independent dilation respectively. After treatment, RH% was increased only in groups B (p <0.05) and C (p <0.001) but not in groups A and D. Plasma levels of PAI-1 and vWF were decreased only in group C (p <0.05 for both), while PAI-1/tPA ratio was significantly decreased in both groups B and C (p <0.05 for both). NTG% and plasma levels of tPA and fVII remained invariable in all groups. In conclusion, combined administration of vitamin C and vitamin E at high dosages, improved endothelial function and decreased plasma levels of PAI-1, vWF and PAI-1/tPA ratio in chronic smokers.

Exaggerated carotid sinus massage responses are related to severe coronary artery disease in patients being evaluated for chest pain.

BACKGROUND: Previous studies have reported that carotid sinus massage responses are associated with advancing age and carotid or coronary artery disease. HYPOTHESIS: This study was undertaken to investigate the potential role of carotid sinus hypersensitivity as a marker for the presence of coronary artery disease, and especially left main stem disease, in patients who were referred for evaluation of chest pain. METHODS: Toward this end, carotid sinus stimulation with simultaneous recordings of the electrocardiogram and aortic pressure was performed before coronary arteriography in 150 selected consecutive patients (mean age 59.4+/-9 years) who were referred for evaluation of chest pain. RESULTS: Coronary artery disease was present in 118 patients (78.7%); of these, 35 had single-vessel disease, 35 had double-vessel disease, 33 had triple-vessel disease, and 15 had left main stem with or without such vessel disease. Carotid sinus hypersensitivity was found in 40 patients (26.6%). The incidence of hypersensitivity in patients with single-, double-, or triple-vessel disease and left main stem disease was 8.5, 14.2, 57.5, and 73.3%, respectively. Stepwise multiple logistic regression analysis revealed that left main stem disease was significantly and independently related to the presence of carotid sinus hypersensitivity (p < 0.05). In addition, the presence of hypersensitivity had 73.3% sensitivity, 86.2% specificity, and 96.3% negative predictive value for the presence of left main stem disease. CONCLUSION: In patients being evaluated for suspected ischemic heart disease, carotid sinus massage responses are related to severe coronary disease. The absence of hypersensitivity may reflect absence of left main stem disease.