Lyme Carditis Complicated by Polymorphic Ventricular Tachycardia and Cardiac Arrest: A Case Report.

Lyme disease is commonly encountered in endemic areas of the United States harboring the causal organism . Lyme carditis can manifest in early disseminated infections, usually as atrioventricular nodal blockade. Timely antibiotic therapy typically suppresses myocardial inflammation and reverses cardiac conduction disturbances.

Heart Rate-Induced Myocardial Ca Retention and Left Ventricular Volume Loss in Patients With Heart Failure With Preserved Ejection Fraction.

Background Increases in heart rate are thought to result in incomplete left ventricular (LV) relaxation and elevated filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). Experimental studies in isolated human myocardium have suggested that incomplete relaxation is a result of cellular Ca overload caused by increased myocardial Na levels. We tested these heart rate paradigms in patients with HFpEF and referent controls without hypertension.

Heart rate-induced modifications of concentric left ventricular hypertrophy: exploration of a novel therapeutic concept.

Lowering the heart rate is considered to be beneficial in heart failure (HF) with reduced ejection fraction (HFrEF). In a dilated left ventricle (LV), pharmacological heart rate lowering is associated with a reduction in LV chamber size. In patients with HFrEF, this structural change is associated with better survival.