`` ```Cardiac arrhythmias````` ` Are disturbances in the heart's rhythm, where the heartbeat may be too fast, too slow, or irregular. These rhythm abnormalities arise due to issues in the heart's electrical conduction system. While some arrhythmias are benign, others can be life-threatening and require prompt medical attention. *Pathophysiology of Arrhythmias* The heart's rhythm is governed by electrical impulses originating from the sinoatrial (SA) node. Arrhythmias occur when there's: - *Abnormal impulse generation*: The SA node generates impulses at an inappropriate rate. - *Abnormal impulse conduction*: Disruptions in the pathways that conduct impulses, leading to delayed or blocked signals. - *Ectopic pacemaker activity*: Other parts of the heart generate impulses, overriding the SA node. Factors contributing to these abnormalities include electrolyte imbalances, ischemia, structural heart disease, and certain medications. 🔍 *Types of Cardiac Arrhythmias* 1. *Bradyarrhythmias (Slow Heart Rate)* - *Definition*: Heart rate less than 60 beats per minute. - *Common Types*: - *Sinus Bradycardia*: Slowed impulse from the SA node. - *Sick Sinus Syndrome*: Malfunctioning SA node leading to alternating slow and fast rhythms. *Atrioventricular (AV) Block*: Delayed or blocked conduction between atria and ventricles. - *Symptoms*: Fatigue, dizziness, syncope, shortness of breath. - *Management*: - Address underlying causes (e.g., medication adjustments). - Pacemaker implantation for symptomatic cases. 2. *Tachyarrhythmias (Fast Heart Rate)* - *Definition*: Heart rate exceeding 100 beats per minute. - *Subtypes*: - *Supraventricular Tachycardia (SVT)*: Rapid rhythms originating above the ventricles. - *Atrial Fibrillation (AFib)*: Irregular, rapid atrial activity leading to an irregular ventricular response. - *Atrial Flutter*: Rapid but regular atrial contractions. - *Ventricular Tachycardia (VT)*: Rapid rhythm originating from the ventricles. - *Ventricular Fibrillation (VF)*: Chaotic ventricular activity leading to ineffective pumping. - *Symptoms*: Palpitations, chest discomfort, lightheadedness, syncope. - *Management*: - Medications: Beta-blockers, calcium channel blockers, antiarrhythmics. - Electrical cardioversion for unstable rhythms. - Catheter ablation for recurrent SVT or AFib. - Implantable cardioverter-defibrillator (ICD) for VT/VF. 3. *Premature Contractions* - *Types*: - *Premature Atrial Contractions (PACs)*: Early atrial beats. *Premature Ventricular Contractions (PVCs)*: Early ventricular beats. - *Symptoms*: Often asymptomatic; may feel like a skipped beat. - *Management*: Usually benign; address triggers like caffeine or stress. 4. *Long QT Syndrome* - *Definition*: Prolonged QT interval on ECG, predisposing to torsades de pointes. - *Causes*: Genetic mutations, certain medications, electrolyte imbalances. - *Symptoms*: Syncope, seizures, sudden cardiac death. - *Management*: - Avoid QT-prolonging drugs. - Beta-blockers. - ICD implantation in high-risk individuals. 🩺 *Diagnostic Tests* - *Electrocardiogram (ECG)*: Primary tool to detect arrhythmias. - *Holter Monitor*: 24-48 hour continuous ECG recording for intermittent arrhythmias. - *Event Monitor*: Patient-activated device for sporadic symptoms. - *Echocardiogram*: Assesses structural heart disease. - *Stress Test*: Evaluates arrhythmias during exercise. - *Electrophysiological Study (EPS)*: Invasive test to map electrical pathways and identify arrhythmia sources.