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.

Arrhythmia means an abnormal heart rhythm. It is a clinical problem in cardiology that involves the cardiac conduction system and myocardial electrical activity. It is commonly discussed in acute care (emergency department, ICU) and longitudinal care (outpatient clinics). It is most often identified and characterized using an electrocardiogram (ECG).

Diastole is the phase of the cardiac cycle when the ventricles relax and fill with blood. It is a core physiology concept used across cardiology, critical care, and cardiovascular imaging. Clinicians discuss Diastole when interpreting blood pressure, heart sounds, and echocardiography findings. It is especially important in conditions involving diastolic dysfunction and heart failure with preserved ejection fraction (HFpEF).

Systole is the phase of the cardiac cycle when the heart muscle contracts to eject blood. It is a core physiology concept used across cardiology, critical care, and anesthesia. Clinicians use it when describing blood pressure, heart sounds, murmurs, and cardiac imaging findings. It is commonly referenced in exams, echocardiography reports, and bedside assessment.

Cardiac Cycle is the repeating sequence of mechanical and electrical events that moves blood through the heart and circulation. It describes how the atria and ventricles fill, contract, and relax with each heartbeat. It is a core physiology concept used across cardiology, including bedside examination, echocardiography, electrocardiography (ECG), and hemodynamics. It is commonly referenced when interpreting heart sounds, murmurs, blood pressure, and ventricular function.

Mean Arterial Pressure is the average arterial blood pressure over one cardiac cycle. It is a core cardiovascular physiology concept used to estimate organ perfusion pressure. It is discussed in acute care, perioperative medicine, cardiology, and critical care monitoring. It is commonly derived from systolic blood pressure and diastolic blood pressure or measured directly with an arterial catheter.