Which condition can directly cause obstructive shock by impairing diastolic filling?

• A. Cardiac tamponade
• B. Hypovolemia
• C. Sepsis
• D. Myocardial infarction

Answer: (A)

Obstructive shock arises when a mechanical problem prevents the heart from filling or pumping effectively, reducing preload and cardiac output. Cardiac tamponade fits this by increasing pericardial pressure that compresses the heart and halts proper ventricular filling during diastole. As diastolic filling is impaired, stroke volume and overall cardiac output fall, leading to hypotension despite the heart itself being structurally intact.

Other options don’t create this mechanical block to filling. Severe hypovolemia lowers circulating volume and preload but doesn’t obstruct filling; sepsis causes vasodilation and distributive shock rather than a filling obstruction; myocardial infarction damages the heart’s pumping ability rather than directly restricting diastolic filling.