- A 70-year-old woman with long-standing hypertension is referred to out-patients with a diagnosis of asymptomatic atrial fibrillation. Echocardiography demonstrates normal left ventricular function, mild LVH and normal mitral valve structure. The left atrium is slightly enlarged (4.2 cm). She is not keen on cardioversion and her rate is well controlled at 70 bpm. What would be the optimal strategy for long-term anticoagulation?
- Aspirin
- Clopidogrel
- Dipyridamole
- Low molecular weight heparin
- Warfarin
0 voters
Atrial fibrillation (AF) is common and affects around 2–5% of the population who are over 60 years old. It confers an approximately fivefold increased risk of stroke. The absolute risk of stroke is related to the coexistence of other cardiovascular disease. In patients with AF and additional risk factors for stroke, such as hypertension, warfarin has been shown to be superior to antiplatelet therapy (primarily aspirin). This patient has evidence of structural cardiac disease with LVH and an enlarged left atrium, thereby reflecting a higher risk of developing a thromboembolic complication. Ongoing studies are evaluating the role of combined antiplatelet therapy, eg aspirin and clopidogrel.
- A 35-year-old woman presented with a history of intermittent light-headedness. Clinical examination and 12-lead electrocardiogram (ECG) were normal. Which of the following, if present on a 24 hour Holter ECG tracing, would be the most clinically important?
- Atrial premature beats
- Profound sleep-associated bradycardia
- Supraventricular tachycardia
- Transient Mobitz type-1 atrioventricular block
- Ventricular premature beats
0 voters
Both atrial and ventricular premature beats are normal variants when seen on a 24 hour Holter electrocardiogram (ECG) tracing. Profound bradycardia may also occur during sleep and is a normal finding. Mobitz type-1 atrioventricular block carries less clinical significance than Mobitz type-2 because the risk of progression to complete heart block is much lower. Thus supraventricular tachycardia (SVT) carries the most clinical significance. Diagnosis of the underlying cause is based on the presence or absence of P-waves and P-wave morphology. Patients can be taught carotid sinus massage to avert SVTs at home, or adenosine can be used in non-asthmatic patients for acute cardioversion to sinus rhythm. Class III anti-arrythmics, such as sotalol, may be considered for prophylaxis.