Cardiology Practice Questions

Q: Hibernating myocardium is:

Seen in chronic severe coronary stenosis. **Explanation:** **Hibernating Myocardium** refers to a state of persistent myocardial dysfunction due to **chronic, severe reduction in coronary blood flow**. The myocardium remains viable but "shuts down" its contractile function to match the low oxygen supply, preventing irreversible necrosis [1]. 1. **Why Option C is Correct:** Hibernating myocardium is a protective adaptation to **chronic severe coronary stenosis**. The hallmark is that the tissue is viable but hypocontractile. Crucially, this dysfunction is **reversible** upon restoration of blood flow (revascularization). 2. **Why Other Options are Incorrect:** * **Option A (Irreversible):** Incorrect. By definition, hibernating myocardium is **reversible**. If the dysfunction were permanent, it would be classified as myocardial infarction (scar tissue). * **Option B (Recovery is spontaneous):** Incorrect. Unlike "Stunned Myocardium" (which recovers spontaneously after an acute event), hibernating myocardium **requires intervention** (PCI or CABG) to restore flow before function can return. * **Option C vs D:** While there is a reduction in both flow and function, the term "mismatch" is more specifically used in PET imaging to describe **preserved glucose uptake (metabolism) despite decreased perfusion**, which identifies the tissue as hibernating. **NEET-PG High-Yield Pearls:** * **Stunned Myocardium:** Acute ischemia followed by reperfusion; function is lost temporarily but recovers *spontaneously*. * **Hibernating Myocardium:** Chronic ischemia; function is lost to preserve viability; recovers *only after revascularization* [1]. * **Gold Standard Investigation:** **PET Scan** (shows FDG uptake/metabolic activity in the absence of flow). * **Clinical Significance:** Identifying hibernating myocardium is vital because these patients benefit significantly from bypass surgery or angioplasty.

Q: Pulsus alternans occurs in which of the following conditions?

Myocardial infarction. Explanation: **Pulsus alternans** is a clinical sign characterized by a regular heart rhythm but with alternating strong and weak pulses. This occurs due to alternating stroke volumes and is a hallmark of **severe left ventricular (LV) systolic dysfunction.** 1. **Why Myocardial Infarction is correct:** A large **Myocardial Infarction (MI)** leads to significant loss of viable myocardium, resulting in acute or chronic LV failure. The mechanism involves the **Frank-Starling law**: after a weak contraction, the end-diastolic volume increases, stretching the fibers and leading to a stronger subsequent contraction [1]. In failing hearts, the recovery of calcium cycling in myocytes is delayed, causing this beat-to-beat variation in contractile force [2]. 2. **Why other options are incorrect:** * **Constrictive Pericarditis:** This is classically associated with **Pulsus Paradoxus** (an exaggerated drop in systolic BP >10 mmHg during inspiration) and Kussmaul’s sign, not pulsus alternans. * **Viral Myocarditis:** While severe myocarditis *can* cause heart failure, MI is the more classic and frequently tested association for pulsus alternans in the context of ischemic cardiomyopathy. * **Hypokalemia:** This typically causes ECG changes (U waves, T-wave flattening, ST depression) and arrhythmias, but does not directly cause mechanical pulsus alternans. **High-Yield Clinical Pearls for NEET-PG:** * **Pulsus Alternans:** Best felt in the **femoral artery**; indicates LV failure. * **Pulsus Paradoxus:** Seen in Cardiac Tamponade, Constrictive Pericarditis, and severe Asthma/COPD. * **Pulsus Bisferiens:** Two systolic peaks; seen in AR, HOCM, and AS+AR. * **Pulsus Parvus et Tardus:** Slow-rising, low-amplitude pulse; classic for **Aortic Stenosis.** * **Electrical Alternans:** Alternating QRS amplitude on ECG; pathognomonic for **Cardiac Tamponade/Massive Pericardial Effusion.**

Q: Reversible myocardial stunning with ECG changes of acute myocardial infarction is seen in which of the following conditions?

Takotsubo cardiomyopathy. **Explanation:** **Takotsubo Cardiomyopathy** (also known as "Broken Heart Syndrome" or "Apical Ballooning Syndrome") is the correct answer. It is characterized by transient, **reversible left ventricular (LV) systolic dysfunction** that typically follows a period of intense physical or emotional stress. * **Pathophysiology:** The condition is thought to be caused by a "catecholamine surge" leading to microvascular spasm or direct myocardial toxicity. This results in **myocardial stunning**, where the heart muscle is alive but temporarily non-functional. * **Clinical Presentation:** Patients present with symptoms identical to an Acute Coronary Syndrome (ACS)—chest pain and dyspnea. * **ECG & Labs:** ECG often shows ST-segment elevation or T-wave inversions, and cardiac enzymes (Troponin) are frequently elevated, mimicking an **Acute Myocardial Infarction (AMI)**. However, coronary angiography reveals **no obstructive coronary artery disease** [1]. **Why other options are incorrect:** * **Restrictive Cardiomyopathy:** Characterized by stiff ventricular walls and impaired diastolic filling; it does not typically present as reversible stunning mimicking an AMI. * **Hypertrophic Cardiomyopathy (HCM):** A genetic disorder causing asymmetrical septal hypertrophy. While it can cause ECG changes (LVH, deep Q waves), it is a chronic structural disease, not a reversible stunning event. * **Dilated Cardiomyopathy (DCM):** Involves progressive enlargement and thinning of the LV. While it causes systolic heart failure, it is generally chronic and irreversible, unlike the transient nature of Takotsubo. **High-Yield Pearls for NEET-PG:** 1. **Classic Imaging Finding:** "Apical ballooning" on ventriculography (resembling a Japanese octopus trap, or *Takotsubo*). 2. **Demographics:** Most common in **postmenopausal women**. 3. **Prognosis:** Excellent; LV function usually returns to normal within 1–4 weeks with supportive care.

Q: A 35-year-old lady presents with a skin lesion and repeated episodes of syncope on sudden change of position. What does the ECG show?

Complete heart block. ***Complete heart block*** - **Positional syncope** in a young patient with skin lesions suggests **cardiac sarcoidosis** or **Lyme carditis**, both commonly causing complete heart block with **Stokes-Adams attacks**. - ECG shows **complete AV dissociation** with independent atrial and ventricular rhythms, causing hemodynamic instability and syncope on position changes. *First-degree heart block* - Characterized by **prolonged PR interval** (>200ms) but all P waves are conducted to ventricles. - Patients remain **asymptomatic** and do not experience syncope as ventricular rate is maintained. *Second-degree heart block* - **Mobitz Type I** shows progressive PR prolongation with dropped beats, while **Mobitz Type II** has fixed PR intervals with intermittent dropped beats. - Usually **asymptomatic** or causes mild symptoms, not severe positional syncope requiring emergency intervention. *2:1 heart block* - Shows **every second P wave** conducted to ventricles with a regular pattern of dropped beats. - While it can cause symptoms, the **regular ventricular response** typically doesn't cause severe positional syncope seen in complete heart block.

Q: What is the most common valvular lesion in carcinoid syndrome?

Tricuspid regurgitation. **Explanation:** Carcinoid heart disease occurs in approximately 50% of patients with carcinoid syndrome, typically associated with metastatic neuroendocrine tumors of the midgut. [1] **Why Tricuspid Regurgitation is correct:** The pathophysiology involves the release of vasoactive substances, primarily **serotonin (5-HT)**, into the systemic circulation. [1] These substances cause fibrous plaque-like endocardial thickening. Because these mediators are inactivated by the lungs (via monoamine oxidase), the **right side of the heart** is predominantly affected. The plaques lead to retraction and fixation of the valve leaflets. The most common manifestation is **Tricuspid Regurgitation (TR)**, often accompanied by pulmonary stenosis. [2] **Why other options are incorrect:** * **Aortic Stenosis (A) & Aortic Regurgitation (D):** Left-sided lesions are rare because the lungs act as a metabolic filter, neutralizing serotonin before it reaches the left atrium. Left-sided involvement only occurs in the presence of a right-to-left shunt (e.g., Patent Foramen Ovale) or primary bronchial carcinoid. * **Mitral Stenosis (C):** Similar to aortic lesions, the mitral valve is protected by pulmonary metabolism. While mitral regurgitation can occur in rare cases, it is never the "most common" lesion. **High-Yield Clinical Pearls for NEET-PG:** * **Pathognomonic finding:** Glistening, white, pearly fibrous plaques on the endocardium. * **Biomarker:** Elevated urinary **5-HIAA** (5-Hydroxyindoleacetic acid) is used for diagnosis. * **Management:** Somatostatin analogues (Octreotide) reduce symptoms; definitive treatment for severe valve heart failure is surgical valve replacement. * **Triad of Carcinoid Syndrome:** Flushing, Diarrhea, and Right-sided heart failure.

Q: All are features of the given ECG except:

Prolonged PR interval. ***Prolonged PR interval*** - **PR interval** represents atrial to ventricular conduction time and is **not applicable** in PVCs since they originate from the **ventricles**, bypassing the normal AV conduction system. - PVCs arise from **ectopic ventricular foci**, making PR interval measurement irrelevant as there is no preceding **P wave** from sinus node activation. *Wide QRS complexes* - PVCs originate from **ventricular myocardium** rather than the normal **His-Purkinje system**, causing slow cell-to-cell conduction. - This abnormal conduction pathway results in **QRS duration >120 ms**, creating the characteristic wide, bizarre morphology. *Absent P wave* - PVCs are **ectopic beats** originating from ventricular tissue, independent of **sinus node** activity. - The **atrial depolarization** (P wave) may be hidden within the wide QRS complex or completely absent due to **retrograde conduction** block. *Complete compensatory pause* - The **sinus node** continues its regular rhythm uninterrupted, creating a pause after the PVC where **two normal R-R intervals** equal the time from the beat before PVC to the beat after. - This occurs because the PVC does **not reset** the sinus node timing, unlike premature atrial contractions which cause incomplete compensatory pauses.

Q: Which of the following is NOT a feature of atrial septal defect?

Paradoxical pulse. **Explanation:** In an Atrial Septal Defect (ASD), the primary pathophysiology involves a left-to-right shunt, leading to volume overload of the right atrium and right ventricle [1]. **Why Paradoxical Pulse is the Correct Answer:** **Pulsus paradoxus** (an exaggerated drop in systolic blood pressure >10 mmHg during inspiration) is typically seen in conditions involving cardiac tamponade, severe asthma, or constrictive pericarditis. It is **not** a feature of ASD. In fact, because the right and left atria communicate in ASD, the normal respiratory variations in stroke volume are dampened, which is why the S2 split remains "fixed." **Analysis of Incorrect Options:** * **Fixed S2 Split:** This is the hallmark of ASD. The split is "wide" due to delayed closure of the pulmonary valve (increased RV volume) and "fixed" because the shunt equalizes the respiratory pressure changes between the two atria. * **Ejection Systolic Murmur (ESM):** This occurs due to **increased flow** across the pulmonary valve (functional pulmonary stenosis). It is heard best at the left upper sternal border. * **Mid-Diastolic Murmur:** This occurs due to **increased flow** across the tricuspid valve (functional tricuspid stenosis) during ventricular filling. It is heard best at the lower left sternal border. **High-Yield Clinical Pearls for NEET-PG:** * **Most common type:** Ostium secundum (located in the region of the fossa ovalis) [1]. * **ECG findings:** Right Axis Deviation and RSR' pattern in V1 (Partial RBBB) are classic for Secundum ASD. * **Chest X-ray:** Shows cardiomegaly, prominent pulmonary artery, and increased pulmonary vascular markings (plethora). * **Contraindication:** ASD closure is contraindicated if Eisenmenger syndrome (reversal of shunt) has developed.

Question 1

Hibernating myocardium is:

Accepted Answer

Seen in chronic severe coronary stenosis

Answer

Irreversible

Answer

Recovery is spontaneous

Answer

Mismatch between flow and function

Question 2

Pulsus alternans occurs in which of the following conditions?

Accepted Answer

Myocardial infarction

Answer

Constrictive pericarditis

Answer

Viral myocarditis

Answer

Hypokalemia

Question 3

A patient with Deep Vein Thrombosis (DVT) on a therapeutic dose of Warfarin presents with complaints of breathlessness and hypotension. Which statement regarding management is true?

Accepted Answer

Maintain INR at 2 and continue Warfarin

Answer

Warfarin to be continued for 6 months

Answer

Maintain INR at 3.5 and continue Warfarin

Answer

Discontinue Warfarin

Question 4

Reversible myocardial stunning with ECG changes of acute myocardial infarction is seen in which of the following conditions?

Accepted Answer

Takotsubo cardiomyopathy

Answer

Restrictive cardiomyopathy

Answer

Hypertrophic cardiomyopathy

Answer

Dilated cardiomyopathy

Question 5

A 35-year-old lady presents with a skin lesion and repeated episodes of syncope on sudden change of position. What does the ECG show?

Accepted Answer

Complete heart block

Answer

First-degree heart block

Answer

Second-degree heart block

Answer

2:1 heart block

Question 6

A 72-year-old man has had poorly controlled hypertension for the past 20 years. Over the past day he has had a severe headache with nausea, followed by confusion, then convulsions. On examination he is afebrile, but his blood pressure is now 260/150 mm Hg. There is bilateral papilledema. Which of the following pathologic lesions is most likely to have developed in his brain during the past day?

Accepted Answer

Arteriolar fibrinoid necrosis

Answer

Cortical telangiectasia

Answer

Lacunar infarction

Answer

Putaminal hematoma

Question 7

What is the most common valvular lesion in carcinoid syndrome?

Accepted Answer

Tricuspid regurgitation

Answer

Aortic stenosis

Answer

Mitral stenosis

Answer

Aortic regurgitation

Question 8

A 60-year-old man presents with dizziness, nausea, and shortness of breath of several months' duration. Physical examination shows hepatomegaly, ascites, and anasarca. His blood pressure is 200/115 mm Hg. A chest X-ray demonstrates cardiomegaly and mild pulmonary edema. Although different mechanisms may have contributed to the pathogenesis of hypertension in this patient, what is the common end result for all of them?

Accepted Answer

Increased peripheral vascular resistance

Answer

Aerial cystic medial necrosis

Answer

Decreased plasma oncotic pressure

Answer

Generalized vasodilation

Question 9

All are features of the given ECG except:

Accepted Answer

Prolonged PR interval

Answer

Wide QRS complexes

Answer

Absent P wave

Answer

Complete compensatory pause

Question 10

Which of the following is NOT a feature of atrial septal defect?

Accepted Answer

Paradoxical pulse

Answer

Fixed S2 split

Answer

Mid diastolic murmur

Answer

Ejection systolic murmur

Cardiology — MCQs

Cardiology — MCQs

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