normal sinus rhythm and ecotopy vs dysrhythmias - Sheet1 Flashcards
What is a normal sinus rhythm?
A normal sinus rhythm refers to the heart rhythm where the electrical impulse originates from the sinoatrial (SA) node, leading to coordinated contraction of the heart.
What does an action potential represent in the heart?
An action potential in the heart signals the electrical impulse that propagates across the myocardium, causing depolarization (contraction) and repolarization (relaxation).
What happens during depolarization?
During depolarization, positively charged sodium (Na+) ions rush into the cells, leading to a change in the membrane potential and initiating heart muscle contraction.
What happens during repolarization?
During repolarization, sodium channels close and potassium (K+) channels open, allowing positively charged potassium ions to exit the cell, returning the cell to a negative resting membrane potential and causing muscle relaxation.
What is ectopy?
Ectopy refers to small changes in an otherwise normal heart rhythm, such as extra or skipped heartbeats. Examples include premature atrial contractions (PACs), premature ventricular contractions (PVCs), and premature junctional contractions (PJCs).
What are the implications of ectopy on cardiac output?
Ectopy generally has minimal impact on cardiac output unless it occurs frequently or in a certain pattern that disrupts normal rhythm significantly.
What are dysrhythmias?
Dysrhythmias are abnormal heart rhythms that can occur due to issues in the electrical system of the heart. They can range from mild to life-threatening.
What are some examples of dysrhythmias?
Examples of dysrhythmias include controlled and uncontrolled atrial fibrillation, atrial flutter, supraventricular tachycardia, various degrees of AV blocks (1st, 2nd, 3rd degree), junctional rhythms, pulseless electrical activity, ventricular tachycardia, ventricular fibrillation, and asystole.
What is the impact of dysrhythmias on cardiac output?
Dysrhythmias can significantly impair cardiac output, especially in cases like ventricular fibrillation or asystole, where effective heart pumping is compromised, leading to reduced blood flow to the body and organs.
What does the P wave represent?
The P wave represents atrial depolarization, which is the electrical activation of the atria, leading to their contraction.
What does the QRS complex represent?
The QRS complex represents ventricular depolarization, which is the electrical activation of the ventricles, leading to their contraction.
What does the T wave represent?
The T wave represents ventricular repolarization, where the ventricles relax and return to their resting state after contraction.
What does the PR interval represent?
The PR interval represents the time it takes for the electrical impulse to travel from the SA node through the AV node, and then to the ventricles. It is measured from the beginning of the P wave to the beginning of the QRS complex.
What does the QT interval represent?
The QT interval represents the time it takes for ventricular depolarization and ventricular repolarization to occur. It is measured from the beginning of the QRS complex to the end of the T wave.
What does the ST segment represent?
The ST segment represents the period between ventricular depolarization and ventricular repolarization. It is important for identifying abnormalities such as ischemia or infarction.
