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Blockade of the skeletal muscle Na(+)-K(+)-ATPase pump by digoxin could result in a more marked hyperkaliema during a forearm exercise, which in turn could stimulate the mechano- and metaboreceptors. In a randomized, double-blinded, placebo-controlled, and cross-over-design study, we measured mean blood pressure (MBP), heart rate (HR), ventilation (V(E)), oxygen saturation (SpO(2)), muscle sympathetic nerve activity (MSNA), venous plasma potassium and lactic acid during dynamic handgrip exercises, and local circulatory arrest in 11 healthy subjects. Digoxin enhanced MBP during exercise but not during the post-handgrip ischemia and had no effect on HR, V(E), SpO(2), and MSNA. Venous plasma potassium and lactic acid were also not affected by digoxin-induced skeletal muscle Na(+)-K(+)-ATPase blockade. We conclude that digoxin increased MBP during dynamic exercise in healthy humans, independently of changes in potassium and lactic acid. A modest direct sensitization of the muscle mechanoreceptors is unlikely and other mechanisms, independent of muscle reflexes and related to the inotropic effects of digoxin, might be implicated. [ABSTRACT FROM AUTHOR]

The article presents a case study in which a 36-year-old nan with paroxysmal atrial fibrillation (AF) and no structural heart disease received a third catheter ablation procedure that was performed in sinus rhythm. The usefulness of adenosine's proarrhythmic effect during AF catheter ablation is mentioned.

Background: The left atrial septal pouch (LASP) is formed by the caudal fusion of the area of overlap of the septum primum and the septum secundum, leaving an opening toward the left atrium. The association between LASP and stroke has not been validated by the previous studies. Methods: The prevalence of the LASP was determined in 223 ischemic stroke patients and 223 control subjects with other cardiac pathologies, in a monocentric retrospective case-control study design. Stroke subtypes were defined according to the modified TOAST criteria. Results: The mean age was 66 ± 15, 54% males, with a high prevalence of cardiovascular risk factors. The prevalence of the LASP was 81 (18%), irrespective of age or pathology. The number of LASP was similar in the stroke and control groups (18% vs. 19%, P = 0.7), as well as in the cryptogenic stroke subgroup (16%, P = 0.6). LASP was not associated with ischemic stroke on univariate (OR = 1.095; 95% CI = 0.676-1.772; P = 0.7) and multivariate logistic regression analysis (OR = 1.004; 95%CI = 0.574-1.758, P = 0.98). There was no statistical association between LASP and cryptogenic stroke on univariate (OR = 1.26; 95%CI = 0.526-3.016; P = 0.6) or multivariate analysis (OR = 0.705; 95%CI = 0.193-2.577, P = 0.6). The association of LASP to AF, left ventricular dysfunction, and thrombophilia did not lead to a higher incidence of stroke (OR = 0.99; 95% CI = 0.37-2.66; P = 0.99). Conclusion: Our study did not show any association between LASP and ischemic stroke. A septal pouch was present in 18% of the population. Other associated risk factors need to be considered to incriminate the septal pouch as the etiology of a stroke. [ABSTRACT FROM AUTHOR]