Third Degree AV Block is complete failure of atrioventricular (AV) conduction between the atria and ventricles. It is a disorder of the cardiac conduction system involving the AV node and/or His–Purkinje system. It is commonly recognized on electrocardiogram (ECG) and bedside monitoring as AV dissociation with bradycardia. It is a clinically important cause of symptomatic bradyarrhythmia and may require pacing therapy.

Second Degree AV Block is a cardiac conduction abnormality in which some atrial impulses fail to conduct to the ventricles. It is defined and recognized primarily on the electrocardiogram (ECG/EKG). It reflects dysfunction within the atrioventricular (AV) conduction pathway, most commonly the AV node or the His–Purkinje system. It is commonly discussed in cardiology, emergency medicine, inpatient telemetry, and perioperative monitoring.

First Degree AV Block is an electrocardiogram (ECG) finding in which atrioventricular (AV) conduction is delayed but not interrupted. It is defined by a prolonged PR interval with every atrial impulse still conducted to the ventricles. It belongs to the cardiac conduction and electrophysiology domain rather than a structural heart disease diagnosis. It is commonly identified on routine ECGs, inpatient telemetry, and preoperative or sports screening.

Heart Block is a problem with electrical conduction from the atria to the ventricles. It is a conduction-system disorder discussed in cardiac anatomy, physiology, and arrhythmia care. It is commonly identified on an electrocardiogram (ECG) and correlated with symptoms like bradycardia or syncope. It matters in emergency assessment, inpatient cardiology, and long-term pacing decisions.

Tachycardia means a heart rate that is faster than expected for age and clinical context. It is a physiologic and pathologic concept in cardiology and acute care medicine. It is most commonly identified at the bedside by pulse and confirmed on electrocardiogram (ECG). It is used to describe a sign, a symptom-associated finding, or a primary cardiac arrhythmia.

Bradycardia means a slower-than-expected heart rate. In adults, it is commonly defined as a resting heart rate below 60 beats per minute (bpm). It is a clinical finding within cardiology and emergency medicine that can be normal or pathologic. It is most often identified on the electrocardiogram (ECG) and bedside vital signs monitoring.

Ventricular Fibrillation is a life-threatening cardiac arrhythmia arising from the ventricles. It causes chaotic, ineffective ventricular electrical activity and loss of organized cardiac output. It is primarily a pathology and emergency rhythm diagnosis in acute care cardiology and resuscitation. It is most commonly recognized on electrocardiogram (ECG) or defibrillator/monitor tracings during sudden collapse.

Ventricular Tachycardia is a fast heart rhythm that starts in the ventricles (the heart’s lower chambers). It is a cardiac arrhythmia and a clinically important diagnosis in acute care and cardiology. It is commonly identified on an electrocardiogram (ECG) and monitored on telemetry. It can occur with structural heart disease or in otherwise normal hearts.

Atrial Flutter is a supraventricular tachycardia caused by an organized re-entrant rhythm in the atria. It is a cardiac arrhythmia discussed in clinical cardiology, emergency care, and electrophysiology. It is commonly recognized on the electrocardiogram (ECG) and managed with rate control, rhythm control, and stroke risk reduction strategies. It often overlaps clinically with atrial fibrillation and other causes of palpitations or tachycardia.

Atrial Fibrillation is a cardiac arrhythmia in which the atria activate rapidly and irregularly. It is a disorder of the heart’s electrical conduction system rather than a valve or coronary artery problem. Clinically, it is discussed in emergency care, inpatient cardiology, outpatient follow-up, and perioperative medicine. It is commonly identified on electrocardiogram (ECG) and managed with rate control, rhythm control, and thromboembolism risk reduction strategies.