Physics of Cardiac Electrophysiology Flashcards
What is cardiac electrophysiology?
The study of the electrical properties and activities of the heart.
True or False: The heart’s electrical activity is solely controlled by the nervous system.
False
What is the primary pacemaker of the heart?
Sinoatrial (SA) node.
Fill in the blank: The electrical impulse travels from the SA node to the ________ node.
Atrioventricular (AV)
Which ion primarily influences cardiac action potentials?
Sodium (Na+)
What does the term ‘refractory period’ refer to in cardiac electrophysiology?
The time during which the heart muscle cannot be stimulated to contract again.
Multiple choice: Which phase of the cardiac action potential is characterized by rapid depolarization? A) Phase 0 B) Phase 1 C) Phase 2 D) Phase 3
A) Phase 0
What is the role of the Purkinje fibers?
To conduct electrical impulses rapidly throughout the ventricles.
True or False: The AV node delays the electrical impulse to allow for ventricular filling.
True
Fill in the blank: The resting membrane potential of cardiac cells is typically around ________ mV.
-90 mV
What is the significance of the threshold potential in cardiac cells?
It is the level of depolarization needed to trigger an action potential.
Multiple choice: What is the effect of sympathetic stimulation on heart rate? A) Increases B) Decreases C) No effect
A) Increases
What does the term ‘electrocardiogram’ (ECG) represent?
A recording of the electrical activity of the heart over time.
Fill in the blank: The ________ segment on an ECG corresponds to the time between atrial depolarization and ventricular depolarization.
PR
What is the primary function of calcium ions in cardiac muscle contraction?
To facilitate the interaction between actin and myosin for contraction.
True or False: Hyperkalemia can lead to increased excitability of cardiac cells.
False
What is the role of the autonomic nervous system in cardiac electrophysiology?
To regulate heart rate and contractility through sympathetic and parasympathetic pathways.
Multiple choice: Which of the following conditions can lead to arrhythmias? A) Ischemia B) Electrolyte imbalances C) Structural heart disease D) All of the above
D) All of the above
Fill in the blank: The ________ wave on an ECG represents ventricular repolarization.
T
What is the significance of the QRS complex on an ECG?
It represents ventricular depolarization.
True or False: The cardiac cycle includes both diastole and systole phases.
True
What does the term ‘chronotropic effect’ refer to?
The influence on heart rate.
Multiple choice: Which ion’s influx is primarily responsible for the plateau phase of the cardiac action potential? A) Na+ B) K+ C) Ca2+ D) Cl-
C) Ca2+
Fill in the blank: The ________ law states that the heart will beat faster in response to increased venous return.
Frank-Starling
