Week 9 Miscellaneous ECG Changes PDF

Potassium is primarily located intracellularly (98%), with only 2% in the extracellular fluid....

Potassium is primarily located intracellularly (98%), with only 2% in the extracellular fluid. The normal serum potassium level is 3.5- 5.0 mmol/L. Potassium is mainly excreted through the kidneys, and its excretion can be promoted reduced potassium excretion and by factors like adrenal insufficiency. potentially higher blood potassium levels Hyperkalemia (serum K+ > 5.1 mmol/L) is the most dangerous electrolyte abnormality. Causes :renal failure, adrenal insufficiency, medications affecting the renin-angiotensin-aldosterone pathway, metabolic acidosis, and tissue trauma. Hyperkalemia 5.5 mmol/L Tall, narrow peaked T waves Hyperkalemia depresses myocardial electrical activity, leading to bradycardia, widening of the QRS complex, and 6.0 mmol/L QRS widens & ST depression ultimately, arrhythmias like sine wave and may occur Potassium (K+) ventricular fibrillation. 6.5 mmol/L PR interval prolongs & P wave flattens 7.0 mmol/L P waves begin to disappear The sine wave is terminal Hypokalemia (serum K+ < 3.5 mmol/L) Electrolyte Abnormalities Causes of hypokalemia include decreased intake, increased gastrointestinal or renal loss, and transcellular Hypokalemia shifts. Hypokalemia delays myocardial cell repolarization, enhances automaticity, and increases cell membrane instability, leading to arrhythmias, potentiates DIGOXIN toxicity ECG changes in hypokalemia include increased P wave amplitude, prolonged PR interval, widened QRS complex, ST segment depression, and the appearance of U waves. treatment:Potassium replacement , Consider replacing Magnesium Ca > 10.5 mg/dL renal disease hyperparathyroidism cancer Hypercalcemia depresses depolarization and neuromuscular activity, leading to shortened QTc interval. Hypercalcemia ECG changes in hypercalcemia include bradycardia, widened QRS complex, shortened ST segment, and depressed T waves. Calcium treatmet Diuresis , Calcitonin Ca < 8.5 mg/L Miscellaneous Hypocalcemia can be caused by chronic ECG Changes renal disease ,acute pancreatitis hypoparathyroidism Decreased extracellular calcium leads to decreased myocardial contractility and altered action potential duration, affecting Hypocalcemia the QTc interval. ECG changes in hypocalcemia include bradycardia, prolonged QTc interval, and flattened or inverted T waves. CALCIUM GLUCONATE, treatment CALCIUM CHLORIDE inflammatory response in the pericardium, resulting in the deposition of various exudates. Pericarditis ECG changes in pericarditis include PR depression, diffuse ST elevation, scooping of the ST segments, and notching of the end of the QRS complex. ECG changes associated with CNS injury, such as subarachnoid hemorrhage, include ST depression, T wave inversion, and prolonged QT interval. Central Nervous System (CNS) Injury These changes are thought to be caused by excessive sympathetic tone and catecholamine production. Other Miscellaneous ECG Changes Hypothermia (core temperature < 35°C) can cause various ECG changes, including tremor artifact, atrial fibrillation with slow ventricular rate, J waves (Osborne waves), bradycardia, and prolongation of the PR, QRS, and QT intervals. Hypothermia Digoxin, a cardiac glycoside, can cause ECG changes such as prolonged PR interval, ST segment depression, T wave inversion or flattening, and increased U wave amplitude. Digoxin Certain antiarrhythmic drugs, as well as other medications, can prolong the QT interval, increasing the risk of torsades de pointes. Class IA antiarrhythmics: quinidine QT-Prolonging Medications Class IC antiarrhythmics: flecainide