Internal Medicine
7 questionsIn the context of ventricular tachycardia, what do extra systoles appear as on an electrocardiogram (ECG)?
What is the most common arrhythmia in ICU patients?
A patient with first-degree heart block presents with dizziness. What is the most appropriate management for this patient?
Hepatic Encephalopathy is predisposed by all, Except:
Which of the following is not typically used for secondary prevention of myocardial infarction?
Which of the following is not recommended for patients with coronary artery disease?
Which one of the following is not an early complication of acute myocardial infarction?
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 601: In the context of ventricular tachycardia, what do extra systoles appear as on an electrocardiogram (ECG)?
- A. P wave
- B. QRS complex (Correct Answer)
- C. T wave
- D. R wave
Explanation: ***QRS complex*** - Extra systoles, particularly **premature ventricular contractions (PVCs)**, originate in the ventricles and result in a **wide and bizarre QRS complex** on an ECG [2]. - The QRS complex represents **ventricular depolarization**, and in ventricular tachycardia, the *ventricular activity* dominates the ECG tracing [2]. *P wave* - The **P wave** represents **atrial depolarization** and is typically either absent or dissociated from the QRS complex in ventricular tachycardia [1], [2]. - Its presence or absence helps differentiate supraventricular from ventricular arrhythmias. *T wave* - The **T wave** represents **ventricular repolarization**, which typically follows the QRS complex [1]. - While it will be present, it often appears abnormal or discordant in ventricular tachycardia due to the altered ventricular depolarization. *R wave* - The **R wave** is part of the QRS complex, specifically the first positive deflection. - While an R wave is present within the QRS complex of an extrasystole, referring to the entire **QRS complex** is more accurate as it encompasses the complete ventricular depolarization in an abnormal morphology.
Question 602: What is the most common arrhythmia in ICU patients?
- A. Atrial flutter
- B. Atrial fibrillation (Correct Answer)
- C. Atrial Tachycardia
- D. Supraventricular Tachycardia
Explanation: ***Atrial fibrillation*** - **Atrial fibrillation (AF)** is the most prevalent arrhythmia in the general population [1], and its incidence is significantly higher in critically ill patients due to various stressors. - Factors like **sepsis**, **hypoxemia**, **electrolyte imbalances**, **myocardial ischemia**, and **inflammatory states** common in the ICU are known triggers for new-onset AF. *Atrial flutter* - While atrial flutter is a common arrhythmia, its overall incidence in the ICU setting is **less frequent than atrial fibrillation**. - It often involves a **re-entrant circuit** in the right atrium [2], leading to characteristic "sawtooth" waves on ECG. *Atrial Tachycardia* - Atrial tachycardia is a form of **supraventricular tachycardia (SVT)** that originates in the atria but is **less common** than AF in the ICU [2]. - It often presents as a **regular, narrow-complex tachycardia** with discrete P waves. *Supraventricular Tachycardia* - This is a broad term encompassing arrhythmias that originate **above the ventricles** [3], including AF, atrial flutter, and atrial tachycardia. - While SVT as a category is common, **atrial fibrillation is the single most frequent specific arrhythmia** within this group in the ICU.
Question 603: A patient with first-degree heart block presents with dizziness. What is the most appropriate management for this patient?
- A. Observation and investigation of other causes (Correct Answer)
- B. Pacemaker insertion
- C. Isoprenaline
- D. Atropine
Explanation: ***Observation and investigation of other causes*** - **First-degree heart block** is usually **asymptomatic** and benign, rarely causing dizziness or other symptoms. - The dizziness experienced by the patient is likely due to another underlying condition and warrants **further investigation** rather than direct intervention for the heart block [2], [3]. *Pacemaker insertion* - **Pacemaker insertion** is reserved for **symptomatic heart blocks** of higher degrees (e.g., Mobitz II or complete heart block) or those with significant hemodynamic compromise [1]. - Given that first-degree heart block is typically asymptomatic, inserting a pacemaker would be an **overtreatment** and unnecessary for this condition alone. *Isoprenaline* - **Isoprenaline** is a **beta-agonist** that increases heart rate and AV conduction, sometimes used in certain bradyarrhythmias. - However, for first-degree heart block, which is generally benign, pharmacologic intervention with agents like **isoprenaline** is not typically indicated and carries risks of adverse effects [2]. *Atropine* - **Atropine** is an anticholinergic drug used to **increase heart rate** by blocking vagal stimulation of the SA and AV nodes. - While it can improve AV conduction, it is not indicated for **asymptomatic first-degree heart block** or when symptoms like dizziness are unlikely to be directly caused by the block itself.
Question 604: Hepatic Encephalopathy is predisposed by all, Except:
- A. Constipation
- B. GI Bleeding
- C. Dehydration
- D. Hyperkalemia (Correct Answer)
Explanation: ***Hyperkalemia*** - **Hyperkalemia** is not a known trigger for hepatic encephalopathy; in fact, **hypokalemia** is a more common electrolyte disturbance that can precipitate it due to its effect on renal ammonia excretion. - Electrolyte imbalances that contribute to hepatic encephalopathy usually involve **hypokalemia**, **hyponatremia**, or **alkalosis**, which affect **ammonia metabolism** and neuronal excitability [1]. *Dehydration* - **Dehydration** can lead to **reduced renal perfusion**, impairing the kidneys' ability to clear **ammonia** and other toxins, thus increasing their concentration in the blood. - It also contributes to **hemoconcentration**, elevating blood **ammonia levels** and increasing the risk of hepatic encephalopathy [1]. *Constipation* - **Constipation** allows for a longer transit time of stool in the colon, providing more opportunity for **intestinal bacteria** to produce **ammonia** from protein breakdown [1]. - The increased production and absorption of ammonia from the gut contribute significantly to the **nitrogenous load** in the bloodstream, predisposing to hepatic encephalopathy [1]. *GI Bleeding* - **Gastrointestinal bleeding** (GI bleeding) introduces a large protein load (blood) into the GI tract, which is then broken down by bacterial action. - This breakdown generates a significant amount of **ammonia** and other nitrogenous compounds, which are then absorbed into the bloodstream, overwhelming the impaired liver's ability to detoxify them and precipitating hepatic encephalopathy [1].
Question 605: Which of the following is not typically used for secondary prevention of myocardial infarction?
- A. Aspirin
- B. Statins
- C. Beta blockers
- D. Warfarin (Correct Answer)
Explanation: ***Warfarin*** - While Warfarin is an **anticoagulant**, its primary role is in preventing *thromboembolism* in conditions like **atrial fibrillation** [1] or **mechanical heart valves**, not routinely for general **secondary prevention of MI** unless specific indications exist. - Unlike the other options, it doesn't directly address the underlying plaque rupture or reduce the workload of the heart in the typical post-MI patient. *Aspirin* - **Aspirin** is a cornerstone of secondary prevention after MI due to its **antiplatelet** effects, which help prevent future clot formation [2]. - It reduces the risk of recurrent MI, stroke, and cardiovascular death by inhibiting **platelet aggregation** [2]. *Statins* - **Statins** are crucial for secondary prevention as they aggressively lower **LDL cholesterol** levels, stabilizing existing plaques and preventing further plaque progression. - They have pleiotropic effects beyond lipid lowering, including **anti-inflammatory** and **endothelial function improvement**. *Beta blockers* - **Beta blockers** reduce myocardial oxygen demand by decreasing heart rate and contractility, which helps prevent recurrent ischemic events and improves survival post-MI [3]. - They are particularly beneficial in patients with **left ventricular dysfunction** or **hypertension** following an MI [1].
Question 606: Which of the following is not recommended for patients with coronary artery disease?
- A. Vitamin E (Correct Answer)
- B. Potassium
- C. Statins
- D. Daily exercise
Explanation: ***Vitamin E*** - **Vitamin E supplements** are generally not recommended for patients with coronary artery disease (CAD) based on current evidence. Some studies suggest a potential link between high doses of vitamin E and an increased risk of **heart failure** or even **overall mortality**. - There is no convincing evidence that vitamin E supplements provide cardiovascular benefits in patients with established CAD, and they may interfere with the efficacy of other beneficial medications like **statins**. *Daily exercise* - **Regular physical activity** is a cornerstone of CAD management, improving cardiovascular fitness, reducing blood pressure, and aiding in weight control [1]. - It helps in preventing disease progression and reducing the risk of future cardiovascular events when performed under appropriate medical guidance [1]. *Potassium* - Maintaining adequate **potassium levels** is crucial for patients with CAD, especially those on diuretics, as it helps regulate **blood pressure** and prevents **cardiac arrhythmias**. - Dietary sources of potassium (fruits, vegetables) are preferred, and supplementation may be necessary for those with deficiencies, but always under medical supervision. *Statins* - **Statins** are a class of medications widely recommended for patients with CAD due to their ability to significantly lower **LDL cholesterol** levels and reduce cardiovascular events [1]. - They stabilize **atherosclerotic plaques** and reduce inflammation, playing a critical role in secondary prevention of heart attacks and strokes [1].
Question 607: Which one of the following is not an early complication of acute myocardial infarction?
- A. Pericarditis
- B. Papillary muscle dysfunction
- C. Ventricular septal defect
- D. Dressler's syndrome (Correct Answer)
Explanation: ***Dressler's syndrome*** - **Dressler's syndrome** (post-myocardial infarction syndrome) is a **late complication** of acute myocardial infarction, typically occurring weeks to months after the event. - It is an **immune-mediated pericarditis**, characterized by chest pain, fever, and pericardial effusion, but is not seen immediately following an MI. *Papillary muscle dysfunction* - **Papillary muscle dysfunction** or rupture can occur as an **early complication** due to ischemia and necrosis of the muscle, leading to **mitral regurgitation** [1]. - This usually manifests within hours to days of the infarct, especially in **inferior MIs** affecting the posterior papillary muscle. *Ventricular septal defect* - A **ventricular septal defect (VSD)** is an **early mechanical complication** resulting from necrosis and rupture of the interventricular septum. - It typically presents within the **first week** after an MI, causing a new **holosystolic murmur** and signs of heart failure. *Pericarditis* - **Early pericarditis** (within a few days of MI) results from inflammation overlying the necrotic myocardial tissue [1]. - It presents with **pleuritic chest pain** that improves with leaning forward and a **pericardial friction rub**, and is distinct from Dressler's syndrome.
Pathology
1 questionsMost common malignant tumor of the heart in adults
NEET-PG 2015 - Pathology NEET-PG Practice Questions and MCQs
Question 601: Most common malignant tumor of the heart in adults
- A. Cardiac Sarcoma (Correct Answer)
- B. Paraganglioma
- C. Rhabdomyoma
- D. Lipoma
Explanation: ***Cardiac Sarcoma*** - **Cardiac sarcomas** are the most common type of **primary malignant tumor** of the heart in adults, accounting for about 95% of primary malignant cardiac tumors. - **Angiosarcoma** is the most common subtype (approximately 33-50% of all cardiac sarcomas), typically originating from the **right atrium**. - These tumors are highly aggressive with rapid growth, early metastasis, and poor prognosis. - They commonly present with right-sided heart failure, pericardial effusion, or constitutional symptoms. *Rhabdomyoma* - **Rhabdomyomas** are the most common **primary cardiac tumors in infants and children** (60-80% of pediatric cardiac tumors), not adults. - These tumors are **benign** and strongly associated with tuberous sclerosis. - They often spontaneously regress after birth. *Lipoma* - **Lipomas** are **benign tumors** composed of mature adipocytes and account for about 10% of benign cardiac tumors. - They are typically asymptomatic and found incidentally. - They are not malignant and therefore not relevant to this question about malignant tumors. *Paraganglioma* - **Paragangliomas** (pheochromocytomas of the heart) are rare neuroendocrine tumors. - They are typically **benign** (though can be locally invasive) and may be hormonally active, causing catecholamine-related symptoms. - They represent less than 1% of cardiac tumors and are not the most common malignant cardiac tumor.
Pharmacology
1 questionsDigitalis is used in mitral stenosis to control the ventricular rate when the patient develops which condition?
NEET-PG 2015 - Pharmacology NEET-PG Practice Questions and MCQs
Question 601: Digitalis is used in mitral stenosis to control the ventricular rate when the patient develops which condition?
- A. Atrial fibrillation (Correct Answer)
- B. Right ventricular failure
- C. Acute pulmonary edema
- D. Myocarditis
Explanation: ***Atrial fibrillation*** - **Digitalis** (digoxin) is effective in **slowing the ventricular rate** in atrial fibrillation by increasing vagal tone and prolonging the refractory period of the AV node. - In **mitral stenosis**, an uncontrolled rapid ventricular rate due to atrial fibrillation can significantly reduce cardiac output and worsen symptoms. *Right ventricular failure* - While digitalis can improve contractility, its primary role in **RV failure** is not rate control; diuretics and afterload reduction are more commonly used. - A patient with isolated right ventricular failure due to mitral stenosis would not directly benefit from digitalis for rate control. *Acute pulmonary edema* - **Acute pulmonary edema** requires rapid diuresis, oxygen, and vasodilators to reduce preload and afterload. - Digitalis has a slower onset of action and is not the first-line treatment for acute pulmonary edema, especially if the cause is not related to a rapid ventricular rate. *Myocarditis* - **Myocarditis** is an inflammation of the heart muscle, and digitalis is generally avoided due to concerns about potentially worsening arrhythmias and myocardial damage in an inflamed heart. - Treatment for myocarditis focuses on supportive care and addressing the underlying cause, not rate control with digitalis unless specific arrhythmias develop.
Physiology
1 questionsWhat is the most common mechanism responsible for causing arrhythmias in the heart?
NEET-PG 2015 - Physiology NEET-PG Practice Questions and MCQs
Question 601: What is the most common mechanism responsible for causing arrhythmias in the heart?
- A. Re-entry (Correct Answer)
- B. Early after depolarization
- C. Late after depolarization
- D. Automaticity
Explanation: ***Re-entry*** - **Re-entry** is the most common mechanism for arrhythmias and involves a re-excitation of cardiac tissue due to a circulating electrical impulse. - This requires at least two pathways with differing conduction velocities and refractory periods, creating a path for the impulse to re-excite an area after its normal refractory period has ended. *Early after depolarization* - **Early afterdepolarizations (EADs)** occur during phase 2 or 3 of the action potential when repolarization is incomplete, often due to prolonged action potential duration. - They are typically associated with conditions like **long QT syndrome** and can trigger polymorphic ventricular tachycardia, but are less common than re-entry. *Late after depolarization* - **Late afterdepolarizations (DADs)** occur during phase 4 of the action potential, after repolarization is complete, due to excessive intracellular calcium. - They are often seen in conditions like **digoxin toxicity** or **catecholaminergic polymorphic ventricular tachycardia**, but are not the most prevalent mechanism. *Automaticity* - **Abnormal automaticity** refers to pacemaker activity arising in non-pacemaker cells or an acceleration of normal pacemaker activity. - While it can cause arrhythmias such as accelerated idioventricular rhythm, re-entry is far more frequently implicated in the etiology of clinical arrhythmias.