Study 04 Cardiovascular Assessment and ECG Interpretation with 12 free online flashcards. Review key terms, definitions, and concepts with this interactive flashcard deck.
What is the normal route of blood through the heart?
Systemic venous blood flows from the right atrium through the tricuspid valve and right ventricle to the lungs; oxygenated blood returns to the left atrium, then passes through the mitral valve and left ventricle to the aorta.
Why does the left ventricle have the greatest muscle mass?
The left ventricle pumps blood against higher systemic resistance, so it has the heart’s greatest muscle mass.
What does a surface ECG not directly measure?
A surface ECG records electrical potential differences; it does not directly measure mechanical contraction, cardiac output, or coronary blood flow.
How do 10 electrodes create a standard 12-lead ECG?
A standard 12-lead ECG uses 10 electrodes: six leads view the heart in the frontal plane and six in the horizontal plane.
What electrical events do the P wave, QRS complex, and T wave represent?
The P wave represents atrial depolarization, the QRS complex ventricular depolarization, and the T wave ventricular repolarization.
At 25 mm per second, how much time does each ECG box represent?
At a paper speed of 25 mm per second, one small box equals 0.04 seconds and one large box equals 0.20 seconds.
How can you estimate rate from a regular ECG rhythm?
For a regular rhythm, estimate rate as large boxes between R waves300 beats per minute.
How do you estimate rate in an irregular rhythm?
Count the QRS complexes in a 6-second strip and multiply by 10; this is more reliable than using one R–R interval when the rhythm is irregular.
Which ECG leads view the inferior region?
Leads II, III, and aVF view the inferior region of the heart.
What ECG pattern is typical of atrial fibrillation?
Atrial fibrillation typically has no consistent discrete P waves and an irregularly irregular ventricular response.
What clue can distinguish atrial flutter from sinus tachycardia near 150 beats per minute?
Atrial flutter has repeating flutter waves, often sawtooth in appearance. With 2:1 conduction, the ventricular rate can be near 150 beats per minute.
What ECG sequence characterizes second-degree AV block, Mobitz I?
In Mobitz I, the PR interval progressively lengthens until a QRS complex is dropped.