Author: Saim Khalid

Introduction The electrocardiogram (ECG) is an indispensable tool in modern medicine, providing a non-invasive window into the electrical activity of the heart. Despite its widespread use, many clinicians and students find ECG interpretation challenging due to the complexity of waveforms, intervals, and axis deviations. Mastering ECG reading is not about memorizing patterns alone—it requires a…

Introduction Electrocardiography (ECG or EKG) is an essential tool in cardiology, providing a non-invasive, rapid assessment of the heart’s electrical activity. While ECG abnormalities often dominate clinical discussions, understanding what constitutes a normal ECG is equally crucial. Accurate knowledge of normal parameters enables clinicians to identify subtle deviations, avoid misdiagnoses, and provide reassurance when findings…

Introduction Electrocardiography (ECG or EKG) is one of the most essential diagnostic tools in modern medicine. It provides a non-invasive method to evaluate the electrical activity of the heart, helping clinicians detect arrhythmias, conduction abnormalities, myocardial ischemia, infarction, and structural heart disease. An accurate understanding of ECG leads—including limb leads, augmented leads, and chest (precordial)…

Introduction The electrocardiogram (ECG or EKG) is one of the most essential diagnostic tools in modern medicine, providing a non-invasive, real-time window into the electrical activity of the heart. Since its invention by Willem Einthoven in the early 20th century, ECG has remained invaluable in diagnosing arrhythmias, conduction abnormalities, myocardial ischemia, electrolyte disturbances, and structural…

Introduction Electrocardiography (ECG or EKG) is one of the most fundamental diagnostic tools in cardiology, offering a window into the heart’s electrical activity. Through a simple, non-invasive procedure, clinicians can detect arrhythmias, ischemia, conduction abnormalities, structural heart disease, and even systemic conditions that impact cardiac function. Despite its apparent simplicity, the ECG is a highly…

Introduction Heart failure (HF) represents one of the most significant public health challenges of the modern era, affecting more than 64 million individuals globally. Despite major advances in device therapy, revascularization, and pharmacology, morbidity and mortality from heart failure remain unacceptably high. For decades, the renin–angiotensin–aldosterone system (RAAS) and sympathetic nervous system (SNS) were the…

Pharmacotherapy of Myocardial Introduction Myocardial ischemia is a pathological state that arises when the blood supply to the heart muscle is insufficient to meet its metabolic demands. The imbalance between oxygen supply and demand leads to cellular hypoxia, anaerobic metabolism, reduced contractility, and—if prolonged—irreversible myocardial injury. Clinically, ischemia manifests most often as angina pectoris, and…

Introduction Heart failure (HF) is not a single disease but a clinical syndrome that arises when the heart is unable to pump blood adequately to meet the body’s metabolic demands or can do so only at elevated filling pressures. It represents the end stage of multiple cardiovascular disorders including ischemic heart disease, hypertension, valvular disorders,…

Introduction Cardiac disease, particularly heart failure, hypertension, and ischemic cardiomyopathy, remains a leading cause of mortality worldwide. A common thread among these conditions is the overactivation of the renin–angiotensin–aldosterone system (RAAS), which promotes vasoconstriction, fluid retention, sympathetic activation, and structural remodeling of the myocardium. Among the most important pharmacological breakthroughs in cardiovascular medicine has been…

Introduction The human heart is an exquisitely regulated organ, orchestrating electrical impulses that drive coordinated contraction and relaxation to sustain life. These impulses are governed by finely tuned interactions between ion channels, transporters, and intracellular signaling pathways. Disturbances in this delicate system often lead to arrhythmias—disorders of rhythm and conduction—that pose significant morbidity and mortality…