NLE Cardiovascular Nursing Reviewer 2026

Answer: A. CO = Heart Rate × Stroke Volume

Step 1 – Recall the definition: Cardiac output is the total volume of blood the heart pumps per minute. Step 2 – Identify the two components: Heart rate (beats per minute) multiplied by stroke volume (mL ejected per beat) gives the total volume per minute. Step 3 – Confirm the normal range: Normal CO is 4–8 L/min. Step 4 – Eliminate wrong options: Blood pressure divided by heart rate has no standard physiologic formula. Stroke volume divided by heart rate reverses the multiplication. Preload × afterload is not a CO formula — these are determinants of stroke volume, not a direct formula.

Answer: C. Sinoatrial (SA) node

Step 1 – Understand the concept: The natural pacemaker is the structure that initiates the electrical impulse that sets the heart's rhythm. Step 2 – Identify the SA node: Located in the right atrium, the SA node fires at 60–100 beats/min — the normal resting heart rate range. Step 3 – Eliminate wrong options: The AV node can act as a backup pacemaker (40–60 bpm) but does not normally initiate the impulse. The Bundle of His and Purkinje fibers are conduction pathways, not impulse-generating nodes. Step 4 – Memorize the hierarchy: SA node → AV node → Bundle of His → Bundle Branches → Purkinje fibers.

Answer: B. Closure of the mitral and tricuspid valves

Step 1 – Recall the sound: S1 is the 'lub' — the first heart sound. Step 2 – Identify its cause: S1 is produced by the simultaneous closure of the mitral (bicuspid) and tricuspid valves, which are the atrioventricular (AV) valves. Step 3 – Link to the cardiac cycle: AV valve closure marks the beginning of systole (ventricular contraction). Step 4 – Eliminate wrong options: Closure of the aortic and pulmonic valves produces S2 ('dub'), which marks the beginning of diastole. Opening of valves does not produce audible sounds under normal conditions. Step 5 – Memory tip: S1 = 1st sound = start of Systole = closure of atrioVentricular valves.

Answer: B. Heart failure and volume overload

Step 1 – Identify S3: It is a low-pitched sound heard early in diastole, after S2, creating a 'lub-dub-da' rhythm also called a ventricular gallop. Step 2 – Know its significance by age: In children and young adults, S3 can be normal. However, in adults over 40, an S3 is abnormal and strongly suggests heart failure with volume overload. Step 3 – Link to pathophysiology: When the ventricle is overfilled (as in heart failure), rapid filling during early diastole creates a vibration heard as S3. Step 4 – Eliminate wrong options: S3 is NOT normal in older adults. Pericarditis produces a pericardial friction rub. Aortic stenosis produces a systolic murmur, not S3. Step 5 – NLE tip: An S3 in an adult = heart failure until proven otherwise.

Answer: C. 0.12 – 0.20 seconds

Step 1 – Recall what the PR interval represents: It is measured from the start of the P wave to the start of the QRS complex. It reflects the time for the impulse to travel from the SA node through the atria and the AV node before reaching the ventricles. Step 2 – Memorize the normal value: 0.12–0.20 seconds (3–5 small boxes on ECG paper). Step 3 – Understand clinical relevance: A PR interval >0.20 seconds indicates a first-degree AV block. Step 4 – Eliminate wrong options: 0.04–0.08 is too short and does not represent any standard interval. 0.06–0.10 is the normal QRS duration. 0.20–0.40 is too prolonged and would indicate AV conduction delay. Step 5 – Memory trick: PR = 0.12–0.20 (think 'twelve to twenty').

Answer: B. Myocardial injury (STEMI)

Step 1 – Know the ST segment: It is the isoelectric line between the QRS complex and the T wave, representing the beginning of ventricular repolarization. Step 2 – Interpret elevation: ST elevation indicates myocardial injury — this is the hallmark of a ST-Elevation Myocardial Infarction (STEMI), a medical emergency requiring immediate intervention. Step 3 – Distinguish from ST depression: ST depression (not elevation) indicates ischemia — reduced blood flow without cell death. Step 4 – Eliminate wrong options: Hyperkalemia produces tall peaked T waves, not ST elevation. Bundle branch block widens the QRS complex. Ischemia causes ST depression, not elevation. Step 5 – NLE clinical priority: ST elevation = STEMI = call the doctor immediately and prepare for reperfusion therapy.

Answer: C. Troponin I

Step 1 – Understand the question: 'Most specific and sensitive' means the marker best identifies myocardial damage with the fewest false positives and negatives. Step 2 – Identify Troponin: Troponin I (and Troponin T) are proteins found almost exclusively in cardiac muscle. When heart cells are injured, they release troponin into the bloodstream. Step 3 – Know the timeline: Troponin rises in 3–6 hours after MI, peaks at 12–24 hours, and remains elevated for up to 10–14 days. Step 4 – Eliminate wrong options: Myoglobin rises earliest (1–3 hours) but is NOT cardiac-specific — it also comes from skeletal muscle. CK-MB is cardiac-specific but less sensitive than troponin. BNP diagnoses heart failure, not MI. Step 5 – NLE key point: Troponin = gold standard for MI diagnosis; serial levels are drawn.

Answer: B. Elevated; suggests heart failure is likely

Step 1 – Know what BNP measures: BNP is released by the ventricles when they are stretched due to increased pressure or volume — a hallmark of heart failure. Step 2 – Know the cut-off value: A BNP below 100 pg/mL makes heart failure unlikely. A BNP above 100 pg/mL (and especially above 400 pg/mL) strongly suggests heart failure. Step 3 – Interpret the given value: 250 pg/mL is above the 100 pg/mL threshold, making heart failure likely. Step 4 – Eliminate wrong options: BNP does NOT diagnose MI — troponin is used for that. BNP is not used specifically to diagnose ischemia. Step 5 – Clinical tip: BNP is also used to monitor treatment response in heart failure patients.

Answer: C. Hypovolemia; patient may need fluid replacement

Step 1 – Recall normal CVP: The normal CVP range is 2–8 mmHg. CVP reflects right ventricular preload and overall fluid volume status. Step 2 – Interpret a low CVP: A CVP of 1 mmHg is below the normal range, indicating hypovolemia (low fluid volume) or decreased venous return. Step 3 – Clinical implication: The patient likely needs fluid resuscitation. The nurse should notify the physician and anticipate IV fluid orders. Step 4 – Interpret a high CVP: A CVP above 8 mmHg suggests fluid overload or right heart failure — the opposite situation. Step 5 – Eliminate wrong options: Fluid overload would cause HIGH CVP. Right heart failure also raises CVP. A normal reading would be 2–8 mmHg, which 1 mmHg is not.

Answer: A. Assess for allergy to iodine, shellfish, or contrast dye

Step 1 – Understand the procedure: Coronary angiography uses iodine-based contrast dye injected into the coronary arteries to visualize blockages. Step 2 – Identify the priority risk: Contrast dye can trigger anaphylaxis in patients allergic to iodine or shellfish. This is a life-threatening complication. The nurse MUST assess for allergy before the procedure. Step 3 – Add renal risk: Contrast dye is also nephrotoxic. Renal function (serum creatinine) must also be assessed. Step 4 – Eliminate wrong options: A 12-lead ECG is not the most critical pre-procedure step. Prophylactic antibiotics are not standard for cardiac catheterization. Restricting fluids for 24 hours is excessive — NPO is typically 6–8 hours; excessive fluid restriction is harmful. Step 5 – NLE priority: Always check allergy to contrast dye FIRST before any procedure using iodine-based contrast.

Answer: A. Atherosclerosis

Step 1: CAD is defined as the progressive narrowing of the coronary arteries that reduces blood flow to the myocardium. Step 2: The most common cause is atherosclerosis — the buildup of fatty, fibrous plaque (atheroma) in the arterial wall (intima). Step 3: This process involves endothelial injury, LDL deposition, inflammation, and fibrous cap formation over time. Step 4: Coronary artery spasm is the cause of Variant (Prinzmetal's) angina, not the most common cause of CAD overall. Step 5: Bacterial endocarditis affects heart valves, and pulmonary embolism involves the pulmonary vasculature — neither is the primary cause of CAD.

Answer: A. Stable angina

Step 1: Stable (exertional) angina is predictable and triggered by physical activity or emotional stress. Step 2: It typically lasts less than 5–15 minutes and is RELIEVED by rest and/or nitroglycerin — the two hallmarks. Step 3: Unstable angina occurs at rest or with minimal exertion and is NOT reliably relieved by rest or nitroglycerin — it signals impending MI. Step 4: Variant (Prinzmetal's) angina is caused by coronary spasm and typically occurs at rest, often at night. Step 5: MI causes pain lasting MORE than 20–30 minutes and is not relieved by nitroglycerin — the key differentiator from stable angina.