Electrocardiography and Heart Failure Management

Electrocardiography

• Definition: A non-invasive test that records the electrical activity of the heart
• Components:
  • P wave: atrial depolarization
  • QRS complex: ventricular depolarization
  • T wave: ventricular repolarization
• Uses:
  • Diagnose arrhythmias, atrial fibrillation, and ventricular fibrillation
  • Identify cardiac chamber enlargement (e.g., left ventricular hypertrophy)
  • Detect myocardial ischemia or infarction

Heart Failure Management

• Stages:
  1. A: High risk of heart failure, but no symptoms
  2. B: Structural heart disease, but no symptoms
  3. C: Symptoms of heart failure, managed with medication
  4. D: Advanced heart failure, requiring specialized care
• Treatment:
  • Medications: ACE inhibitors, beta blockers, diuretics
  • Lifestyle changes: salt restriction, exercise, weight management
  • Devices: implantable cardioverter-defibrillators (ICDs), cardiac resynchronization therapy (CRT)

Cardiac Pharmacology

• Medications:
  • Antiplatelet agents: aspirin, clopidogrel, prasugrel
  • Anticoagulants: warfarin, dabigatran, rivaroxaban
  • Beta blockers: metoprolol, carvedilol, bisoprolol
  • Calcium channel blockers: verapamil, diltiazem, nifedipine
• Indications:
  • Acute coronary syndrome (ACS)
  • Atrial fibrillation
  • Hypertension
  • Heart failure

Cardiac Imaging

• Modalities:
  1. Echocardiography: ultrasound-based imaging of the heart
  2. Cardiac MRI: magnetic resonance imaging of the heart
  3. Cardiac CT: computed tomography of the heart
• Uses:
  • Evaluate cardiac structure and function
  • Diagnose coronary artery disease
  • Detect cardiac tumors and masses

Cardiac Embryology

• Developmental stages:
  1. Cardiac tube formation: 3-4 weeks
  2. Cardiac looping: 4-5 weeks
  3. Septation: 5-8 weeks
• Anomalies:
  • Atrial septal defects (ASD)
  • Ventricular septal defects (VSD)
  • Tetralogy of Fallot

Congenital Heart Diseases

• Classification:
  1. Acyanotic: left-to-right shunts (e.g., ASD, VSD)
  2. Cyanotic: right-to-left shunts (e.g., tetralogy of Fallot)
• Examples:
  • Patent ductus arteriosus (PDA)
  • Coarctation of the aorta
  • Transposition of the great arteries

Hypertension

• Definition: Blood pressure ≥ 140/90 mmHg
• Types:
  1. Essential hypertension: primary hypertension, no underlying cause
  2. Secondary hypertension: hypertension due to underlying condition (e.g., kidney disease)
• Complications:
  • Cardiovascular disease
  • Kidney disease
  • Stroke

Aortic Aneurysm

• Definition: dilation of the aortic wall
• Types:
  1. Thoracic aortic aneurysm: aneurysm in the thoracic aorta
  2. Abdominal aortic aneurysm: aneurysm in the abdominal aorta
• Risk factors:
  • Hypertension
  • Atherosclerosis
  • Family history

Myocardial Infarction

• Definition: death of myocardial tissue due to ischemia
• Types:
  1. ST-elevation MI (STEMI): transmural infarction
  2. Non-ST elevation MI (NSTEMI): non-transmural infarction
• Treatment:
  • Thrombolytics: dissolve blood clots
  • Percutaneous coronary intervention (PCI): angioplasty and stenting
  • Coronary artery bypass grafting (CABG): surgical revascularization

Heart Blocks

• Definition: impairment of electrical conduction in the heart
• Types:
  1. First-degree AV block: prolonged PR interval
  2. Second-degree AV block: intermittent blocking of electrical conduction
  3. Third-degree AV block: complete block of electrical conduction
• Causes:
  • Myocardial infarction
  • Cardiac sarcoidosis
  • Lyme disease

Arrhythmias

• Definition: abnormal heart rhythms
• Types:
  1. Supraventricular arrhythmias: originate above the ventricles
     • Atrial fibrillation
     • Atrial flutter
  2. Ventricular arrhythmias: originate in the ventricles
     • Ventricular fibrillation
     • Ventricular tachycardia
• Causes:
  • Electrolyte imbalance
  • Cardiac disease
  • Medications

Electrocardiography

• Non-invasive test that records the electrical activity of the heart
• Consists of P wave, QRS complex, and T wave, which represent atrial depolarization, ventricular depolarization, and ventricular repolarization, respectively
• Used to diagnose arrhythmias, atrial fibrillation, ventricular fibrillation, and identify cardiac chamber enlargement and myocardial ischemia or infarction

Heart Failure Management

• Classified into four stages: A, B, C, and D, based on risk and symptoms
• Stage A: high risk of heart failure, but no symptoms
• Stage B: structural heart disease, but no symptoms
• Stage C: symptoms of heart failure, managed with medication
• Stage D: advanced heart failure, requiring specialized care
• Treatment includes medications, lifestyle changes, and devices such as ACE inhibitors, beta blockers, diuretics, salt restriction, exercise, weight management, implantable cardioverter-defibrillators, and cardiac resynchronization therapy

Cardiac Pharmacology

• Medications used to treat various cardiac conditions include antiplatelet agents, anticoagulants, beta blockers, and calcium channel blockers
• Antiplatelet agents: aspirin, clopidogrel, prasugrel
• Anticoagulants: warfarin, dabigatran, rivaroxaban
• Beta blockers: metoprolol, carvedilol, bisoprolol
• Calcium channel blockers: verapamil, diltiazem, nifedipine
• Indications for these medications include acute coronary syndrome, atrial fibrillation, hypertension, and heart failure

Cardiac Imaging

• Modalities used to evaluate cardiac structure and function include echocardiography, cardiac MRI, and cardiac CT
• Echocardiography: ultrasound-based imaging of the heart
• Cardiac MRI: magnetic resonance imaging of the heart
• Cardiac CT: computed tomography of the heart
• Uses of cardiac imaging include diagnosing coronary artery disease and detecting cardiac tumors and masses

Cardiac Embryology

• Developmental stages of the heart include cardiac tube formation, cardiac looping, and septation
• Cardiac tube formation occurs at 3-4 weeks
• Cardiac looping occurs at 4-5 weeks
• Septation occurs at 5-8 weeks
• Anomalies that can occur during cardiac development include atrial septal defects, ventricular septal defects, and tetralogy of Fallot

Congenital Heart Diseases

• Classified into acyanotic and cyanotic heart diseases
• Acyanotic heart diseases: left-to-right shunts, e.g., ASD, VSD
• Cyanotic heart diseases: right-to-left shunts, e.g., tetralogy of Fallot
• Examples of congenital heart diseases include patent ductus arteriosus, coarctation of the aorta, and transposition of the great arteries

Hypertension

• Defined as blood pressure ≥ 140/90 mmHg
• Classified into essential hypertension and secondary hypertension
• Essential hypertension: primary hypertension, no underlying cause
• Secondary hypertension: hypertension due to underlying condition, e.g., kidney disease
• Complications of hypertension include cardiovascular disease, kidney disease, and stroke

Aortic Aneurysm

• Defined as dilation of the aortic wall
• Classified into thoracic aortic aneurysm and abdominal aortic aneurysm
• Risk factors for aortic aneurysm include hypertension, atherosclerosis, and family history

Myocardial Infarction

• Defined as death of myocardial tissue due to ischemia
• Classified into ST-elevation MI and non-ST elevation MI
• ST-elevation MI: transmural infarction
• Non-ST elevation MI: non-transmural infarction
• Treatment options include thrombolytics, percutaneous coronary intervention, and coronary artery bypass grafting

Heart Blocks

• Defined as impairment of electrical conduction in the heart
• Classified into first-degree, second-degree, and third-degree AV block
• First-degree AV block: prolonged PR interval
• Second-degree AV block: intermittent blocking of electrical conduction
• Third-degree AV block: complete block of electrical conduction
• Causes of heart block include myocardial infarction, cardiac sarcoidosis, and Lyme disease

Arrhythmias

• Defined as abnormal heart rhythms
• Classified into supraventricular arrhythmias and ventricular arrhythmias
• Supraventricular arrhythmias: originate above the ventricles
• Examples of supraventricular arrhythmias include atrial fibrillation and atrial flutter
• Ventricular arrhythmias: originate in the ventricles

Learn about electrocardiography, a non-invasive test that records the heart's electrical activity, and its uses in diagnosing heart conditions, as well as stages of heart failure management.