John James
Patient Safety America, Houston, 77062, USA
Title: Potassium and Magnesium – Essentials for Cardiac Performance
Biography
Biography: John James
Abstract
Potassium and magnesium are essential electrolytes for optimization of cardiac function, especially when the heart is stressed by physical demands, structural abnormalities, or emotional situations. A seminal case study of the tragic interplay of these factors will be described in a young runner, beginning at the molecular level. From the molecular level, the effects on the electrical performance of the heart will be characterized as the gateway to life-threatening arrhythmias, including numerous ectopic beats (premature ventricular contractions), prolongation of the corrected QT interval, and high dispersion of the QT intervals evident in the electrocardiogram. Medical guidelines from the National Council on Potassium in Clinical Practice and diagnostic criteria for long QT syndrome related to the case study will be described. Attention will be drawn to the diurnal variation of potassium levels as a masking-factor for life-threatening arrhythmias. Ultimately, data from studies in potassium-depleted animals will show that cardiac lesions characteristic of morphological injury to the heart, namely foci of heart-cell necrosis infiltrated by mononuclear cells and having early evidence of fibrosis, occurred with potassium depletion in the case study. This harmful effect on the heart is not well known. The present case study demonstrates the general need for more attention to electrolytes in cardiac function, especially to depletion of potassium and magnesium. Factors leading to depletion of these electrolytes will be surveyed. These include diuretic medications, intense exercise in hot climates, and diets lacking foods rich in potassium and magnesium.