A 65-year-old man presents to the GP for a routine hypertension check-up. He has a medical history of hypertension, ischaemic heart disease, osteoarthritis, rheumatic fever and COPD.
During the physical examination, the GP hears a mid-late diastolic murmur that intensifies during expiration. The GP suspects that the patient may have mitral stenosis.
What is the primary cause of this abnormality?
A 25-year-old man is scheduled for cardiac catheterisation to repair a possible atrial septal defect. What is the typical oxygen saturation level in the right atrium for a person in good health?
A patient’s ECG displays broad complex QRS complexes, indicating a possible ventricular origin issue or aberrant conduction. What is the typical resting membrane potential of ventricular contractile fibers in the heart?
A 72-year-old woman is prescribed digoxin for the treatment of atrial fibrillation that was not effectively managed with atenolol alone. Digoxin works by inhibiting a crucial element in the cardiac action potential that restores resting potential. This inhibition leads to changes in the levels of specific ions on either side of the membrane, resulting in an enhanced contractile force of the heart and an improvement in left ventricular ejection fraction.
Which element does digoxin inhibit to achieve this effect?
A patient with chronic heart failure with reduced ejection fraction has been prescribed a new medication as part of their drug regimen. This drug aims to improve myocardial contractility, but it is also associated with various side effects, such as arrhythmias. Its mechanism of action is blocking a protein with an important role in the resting potential of cardiac muscle cells.
What protein is the drug targeting?
Where are the red hat pins most likely located based on the highest velocity measurements in different parts of a bovine heart during experimental research for a new drug for heart conduction disorders?
Which of the following is accountable for the swift depolarization phase of the cardiac action potential?
A 67-year-old woman arrives at the emergency department complaining of palpitations. Upon examination, her ECG reveals tall tented T waves. What causes the distinctive shape of the T wave, which corresponds to phase 3 of the cardiac action potential?
A 67-year-old man is brought to the emergency department with unilateral weakness and loss of sensation. He is later diagnosed with an ischaemic stroke. After initial treatment, he is started on dipyridamole as part of his ongoing therapy.
What is the mechanism of action of dipyridamole?
Which of the following complications is the least commonly associated with ventricular septal defects in pediatric patients?