The heart rate is the number of beats per minute. On average, an adult human’s heart beats around 70-75 beats per minute. A precise way of measuring the heart rate is the electrocardiograph (EKG). EKG’s can diagnose the condition of the heart by reading the electrical waves that travel through the cardiac muscle during the heart cycle. There are three main electrical signals that are graphed on an EKG: the P, QRS and T waves. Each wave represents a different part of the heartbeat or cardiac cycle.
EKG’s are used very frequently in hospitals or other clinical settings, especially when the patient is in critical condition. An electrocardiogram is often taken not only when the patient is at rest but at work, such as riding a stationary bicycle or running on a treadmill; this gives a more accurate image of the health of the patient’s heart. Below are three diseases and conditions of the heart that can be detected using an electrocardiogram.
Arrhythmia is a term that refers to unusual beating patterns in the heart. For example the heart may beat much faster (tachycardia) or slower (bradycardia) than normal, or it may beat erratically (fibrillation).
Fibrillation is when the heart quivers but doesn’t produce the coordinated pumping action needed to push the blood through the heart and out into the body. There are two types of heart fibrillation, atrial and ventricular.
Atrial fibrillation occurs when the atria quiver instead of pumping effectively. Because the blood is not fully pumped out it can cause it to form a pool and start to clot. A stroke occurs if a piece of this blood clot leaves the heart and becomes stuck in an artery in the brain. On the EKG, no P-waves are seen due to the chaotic atrial depolarization. The QRS complexes have normal shape, due to normal ventricular conduction.
Ventricular fibrillation is life-threatening and can cause a heart attack without much warning. It occurs when the ventricles are unable to pump blood; the pulse weakens and unconsciousness quickly follows. If cardiac arrest follows, CPR must be performed immediately after cardiac arrest to ensure the survival of the person. Ventricular fibrillation is common in people who have coronary heart disease, which is when the arteries become narrowed. On an ECG the waves are irregular and random. There is no apparent QRS wave.Other symptoms that may require surgery can be identified by an EKG, such as pericarditis.