What is a condition where the walls of the arteries in the lungs become thickened and stiff, leading to increased blood pressure in the pulmonary arteries?

Correct Answer: A

Rationale: The correct answer is A: Pulmonary hypertension. Pulmonary hypertension refers to the condition where the walls of the arteries in the lungs become thickened and stiff, leading to increased blood pressure in the pulmonary arteries. This results in the heart having to work harder to pump blood through the lungs, causing potential damage to the heart and lungs over time. B: Pulmonary fibrosis is a condition characterized by scarring of lung tissue, not thickening and stiffening of artery walls. C: Pulmonary embolism is a blockage in one of the pulmonary arteries in your lungs, usually caused by a blood clot. It does not involve thickening and stiffening of artery walls. D: Pulmonary edema is a condition where fluid builds up in the lungs, causing difficulty in breathing. It is not related to thickened and stiffened artery walls.

Correct Answer: A

Rationale: The correct answer is A: Cor pulmonale. Cor pulmonale is right-sided heart failure due to increased pressure in the pulmonary arteries, typically caused by chronic lung disease. This leads to the right side of the heart working harder to pump blood through the lungs, resulting in eventual failure. Pulmonary embolism (C) is a sudden blockage in the pulmonary artery, not a chronic condition. Heart failure (B) is a general term for when the heart is unable to pump blood effectively, not specific to the right side. Myocarditis (D) is inflammation of the heart muscle, not directly related to pulmonary hypertension.

Correct Answer: A

Rationale: The PR interval measures the time it takes for the electrical signal to travel from the atria to the ventricles, reflecting atrial depolarization and the delay at the AV node before ventricular activation. Option A is correct as it accurately describes the PR interval. Option B is incorrect as the PR interval does not measure ventricular depolarization. Option C is incorrect as the PR interval does not represent ventricular repolarization. Option D is incorrect as it describes the QT interval, not the PR interval.

Correct Answer: A

Rationale: The correct answer is A: Arrhythmia. Arrhythmia refers to an irregular heartbeat caused by malfunctioning of the heart's electrical system. Bradycardia (B) is a slow heart rate, Tachycardia (C) is a fast heart rate, and Ventricular fibrillation (D) is a life-threatening arrhythmia characterized by rapid, irregular heartbeats. Arrhythmia encompasses various types of irregular heart rhythms, making it the most appropriate choice in this context.

Correct Answer: A

Rationale: Myocarditis is the correct answer because it specifically refers to inflammation of the heart muscle often caused by a viral infection, leading to impaired heart function. It directly addresses the condition described in the question. Endocarditis is inflammation of the inner lining of the heart chambers and valves, not the heart muscle. Pericarditis is inflammation of the outer lining of the heart, not the heart muscle. Cardiomyopathy is a general term for diseases of the heart muscle that impair its ability to pump blood, but it does not specifically mention inflammation caused by viral infections.