patients with RCM. Anticoagulation is required in patients with atrial fibrillation, mural thrombus, or evidence of systemic embolisation to prevent strokes. Left ventricular assist device may be beneficial in patients with advanced heart failure as a definitive therapy or as a bridge to cardiac transplant.
Muchtar E, Blauwet L, Gertz M. Restrictive Cardiomyopathy: Genetics, Pathogenesis, Clinical Manifestations, Diagnosis, and Therapy. Circulation Research. 2017;121(7):819–837.
https://www.ncbi.nlm.nih.gov/pubmed/28912185
28. Answer: D
Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) remain a significant cause of cardiovascular morbidity and mortality worldwide. In Australia, ARF and RHD disproportionately affect the ATSI population, with up to ×10 higher incidence, ×8 higher ARF hospitalisation rates, and ×20 higher mortality. The highest rates of ARF are in children aged 5–14 years old, and highest rates of RHD in adults aged 35–39, with an all‐age RHD incidence up to 2% in ATSI populations in the Northern Territory.
All patients with suspected ARF should be hospitalised to enable appropriate diagnostic investigations including echocardiogram. In high risk groups there should be a lower threshold for diagnosis as listed below and high‐risk groups are populations with an incidence of ARF >30/100 000 per year in 5–14 years old or incidence of RHD >2/1000 in all age groups.
ARF diagnosis requires evidence of a preceding group A streptococcus infection, and two major manifestations or one major manifestation and two minor manifestations listed below in low risk populations:
Major manifestations:Carditis (including subclinical evidence of rheumatic valve disease on echocardiograms)Polyarthritis or aseptic monoarthritis or polyarthralgiaChoreaSubcutaneous nodulesErythema marginatum.
Minor manifestations:FeverPolyarthralgia or aseptic monoarthritisESR ≥30 mm/hr or CRP ≥30 mg/LProlonged PR interval on ECG.
Treatment of ARF is benzathine penicillin G every four week, or every three week for high risk patients, for a minimum of 10 years after the last episode of ARF, or until aged 21 if no RHD or 35–40 if moderate–severe RHD.
ARF RHD Guideline [Internet]. Rheumatic Heart Disease Australia. 2019 [cited 19 August 2019]. Available from: https://www.rhdaustralia.org.au/arf‐rhd‐guideline
29. Answer: D
This patient's presentation and ECG changes are consistent with inferior and right ventricular (RV) myocardial infarction (MI). RV ischaemia complicates 30% to 50% of inferior MIs. Isolated RV myocardial infarction (RVMI) is rare. The coronary artery involved is usually an occluded right coronary artery (RCA). The proximal segment of the RCA supplies the sinoatrial (SA) node and the right atrial wall; the middle segment supplies the lateral and inferior right ventricle (RV); and the posterior portion of the left ventricle, the inferior septum, inferior left ventricular wall and atrioventricular (AV) node are perfused by the distal segment of the RCA. A few patients (10%) may have a right ventricle that is supplied by the circumflex artery.
Although the RVMI often shows good long‐term recovery, in the short term RVMI has a worse prognosis to uncomplicated inferior MI, with haemodynamic and electrophysiologic complications increasing in‐hospital morbidity and mortality. Acute RV shock has an equally high mortality to left ventricular (LV) shock.
Clinically, the triad of hypotension, elevated jugular venous pressure (JVP), and clear lung fields should raise the possibility of RVMI in patients with acute inferior MI. The classic 12 lead ECG provides information on the LV, but limited information on the electrical activity of the RV. Only lead V1 provides a partial view of the RV free wall. Right precordial leads are obtained by placing the precordial electrodes over the right chest in positions mirroring their usual arrangement. The presence of acute ST segment elevation, Q waves or both in the right precordial leads (V3R to V6R), is highly reliable in the diagnosis of RVMI. ST segment elevation 0.1 mV in the right precordial leads, especially V4R, is observed in 60–90% of patients with acute RVMI. ST elevation from the RV free wall may also be detected by ST elevation in lead III being more than that in lead II or by reciprocal ST depression in leads I and aVL. Echocardiogram should be performed in patient with or suspected RVMI. It may show RV dysfunction. Additional features of RV involvement include paradoxical septal motion due to increased RV end diastolic pressure, tricuspid regurgitation, and increased right heart pressure.
Cardiac MRI (CMR) can directly evaluate RV size, mass, morphology, and function in an accurate and reproducible manner. CMR is now considered the gold standard for non‐invasive assessment of RV function, particularly as it provides additional information on RV anatomy and myocardial mass.
It is important to recognise and diagnose RVMI, as the treatment is different to LVMI and inferior MI. Please see the following principles of the RVMI management.
1 Reperfusion therapyPrimary percutaneous coronary intervention preferable to thrombolysis, this should be performed as early as possible to preserve right heart function.
2 Optimise RV preloadAvoid morphine, diuretics, β‐blockers, nitrates, ACE inhibitorTrial of judicious fluid administration in the absence of pulmonary oedemaConsider intravenous fluid therapy to increase right sided preload in the absence of pulmonary oedema.
1 Reduce RV afterloadInotropes, pulmonary vasodilators (nitric oxide, prostacycline)Intra‐aortic balloon pump.
1 Maintain chronotropic competence and atrioventricular synchronyAvoid β‐blockers in patients with proximal right coronary artery occlusionConsider dual‐chamber temporary pacing.
Kakouros N, Cokkinos D. Right ventricular myocardial infarction: pathophysiology, diagnosis, and management. Postgraduate Medical Journal. 2010;86(1022):719–728.
https://www.ncbi.nlm.nih.gov/pubmed/20956396
30. Answer: D
Permanent pacing for sinus node dysfunction is only indicated in patients with symptoms directly attributable to bradycardia, irrespective of minimum heart rate or pause duration.
Sinus node dysfunction is most often related to age‐dependent progressive fibrosis of the sinus nodal tissue and surrounding atrial myocardium. It may lead to abnormalities of the sinus node, and atrial impulse formation and propagation, which will therefore result in various bradycardic or pause‐related syndromes. Less common causes include acute myocardial ischemia, atrial tachyarrhythmias, electrolyte abnormalities, hypothyroidism, medications, infections, and metabolic abnormalities. Evaluation for these potentially treatable or reversible causes can be performed non‐urgently in most cases.
Nocturnal bradycardias should prompt consideration of screening for sleep apnoea. Nocturnal bradycardias are common in patient with sleep apnoea. Treatment of sleep apnoea not only reduces the frequency of nocturnal bradycardias but also might offer cardiovascular
