Australian Doctor Australian Doctor 7th July 2017 | Page 26

How to Treat – Myocarditis from previous page and left axis deviation — hall- marks suggesting ventricular ori- gin. He is urgently transferred to the nearest hospital. The tachy- cardia is eventually terminated by electrical cardioversion (single 200J biphasic shock) one hour after admission to the ED. Twelve hours later, high-sensi- tivity troponin T is significantly elevated at 600ng/mL (normal is less than 14ng/mL), and transtho- racic echocardiogram shows mild left ventricular dilatation and sys- to lic dysfunction (left ventricular ejection fraction of 42%), with left ventricular wall motion abnor- malities in the inferior and lateral leads. Further short runs of VT are observed. Urgent invasive coronary angi- ography demonstrates normal coronary arteries. A CMR scan confirms segmental wall motion abnormalities, as raised by the echocardiogram. Additionally, cir- cumferential subepicardial delayed gadolinium enhancement is noted and is more evident within the inferior basal left ventricular wall, suggesting focal areas of irrevers- ible infarction. Further cardio- tropic viral serology and cardiac autoantibody tests are negative. Because of recurrent episodes of Conclusion ECG VT. VT, refractory to IV amiodarone, lignocaine, beta blockers and mag- nesium sulphate, Allan is trans- ferred to a tertiary centre for VT radiofrequency catheter ablation. During unipolar and bipolar left ventricular endocardial mapping using the CARTO 3 system, it is demonstrated that the VT exit site is located in the left ventricular basal inferior segment. After mul- tiple consecutive radiofrequency pulses from the left ventricular inferior wall to the basal interven- tricular septum, no further VT or VF is inducible. up to five minutes. Repeat cardiac MRI shows slight deterioration of left ventricular function with an ejection fraction of 40%. There is almost transmural gadolinium enhancement of the inferior wall and the septum, indicating pro- gression of the underlying disease process. VT ablation is repeated, with no recurrent VT during a further six- month follow-up period. Repeat Holter shows infrequent ventricu- lar ectopy; however, the left ven- tricular ejection fraction remains mildly impaired. EMB performed just prior to VT ablation shows acute lymphocytic infiltration of the myocardium, consistent with active myocarditis. Viral genome amplification using PCR is attempted but remains neg- ative, and an autoimmune origin is suspected. The initial therapy is support- ive, using ACE inhibitors and beta blockers; however, a pulsed course of prednisone is prescribed. At three-month follow-up, 24-hour Holter monitoring demonstrates 35% ventricular ectopy, as well as short runs of (asymptomatic) VT MYOCARDITIS resulting from infectious and non-infectious causes has a wide range of clini- cal presentations. Viral infection is responsible for the majority of cases. During the course of the disease, the majority of patients recover spontaneously, but a small number of cases progress to dilated cardiomyopathy or die. Patients with fulminant myo- carditis develop an acute onset of haemodynamic instability, requir- ing early detection and aggres- sive treatment. They have a better prognosis than the non-fulminant cases. CMR-guided EMB should be considered in a select group of patients to establish the diagno- sis, as well as for prognostication. Currently, treatment is largely supportive. References Available on request from [email protected] How to Treat Quiz GO ONLINE TO COMPLETE THE QUIZ Myocarditis — 7 July 2017 www.australiandoctor.com.au/education/how-to-treat 1. Which THREE statements regarding myocarditis are correct? a) The diverse clinical presentations make the diagnosis of myocarditis challenging. b) The pathophysiology of myocarditis is well documented and aids in the management of this condition. c) It is often diagnosed by exclusion of other cardiac diseases. d) A viral infection is the most common cause of the disease. 2. Which TWO criteria are included in the WHO definition of myocarditis? a) Histological b) Physical c) Immunological d) Radiological 3. Which THREE are broad aetiologies of myocarditis? a) Infectious b) Immune-mediated c) Toxic d) Hereditary 4. Which TWO statements regarding the pathogenesis of myocarditis are correct? a) Virus-induced myocarditis is a progressive disease process with a sequence of three pathologically distinct phases. b) The three stages include viraemia, myocyte necrosis and antibody proliferation. c) Immunocompromised patients recover as well as non- immunocompromised patients when antibiotics are administered in sufficiently high doses over a long enough period. d) Although the molecular and cellular pathophysiology may differ between different aetiologies, cellular infiltration, oedema, necrosis and fibrotic scars in a later stage are common features. 5. Which THREE statements regarding the clinical presentation of myocarditis are correct? a) All patients with myocarditis will complain of several symptoms, which may include fatigue, chest pain and nausea. b) Acute myocarditis is mainly a self- limited illness with spontaneous complete resolution. c) Fulminant myocarditis is a distinct 8. Which TWO statements regarding the diagnosis of myocarditis are correct? a) Serological examinations should no longer be used as a standard evaluation in the diagnostic workup of patients with suspected myocarditis. b) Disease-specific serum cardiac autoantibodies for myocarditis are associated with a better prognosis in chronic myocarditis and a worse outcome in acute cases. c) Echocardiography and contrast- enhanced cardiovascular magnetic resonance (CMR) are standard imaging tools in patients with suspected myocarditis. d) There are several well-described and diagnostic features of myocardial inflammation on echocardiography. entity, characterised by severe haemodynamic compromise, cardiogenic shock or fatal arrhythmia at presentation. d) In patients with acute or chronic myocarditis, arrhythmia may be the only clinical symptom. 6. Which TWO may be features of myocarditis? a) Cor pulmonale b) Acute chest pain c) Hypertension d) Heart failure 7. Which THREE statements regarding the diagnosis of myocarditis are correct? a) An accurate diagnosis should use an integrated assessment that incorporates clinical assessment, ECG, serum biomarkers, non-invasive imaging and endomyocardial biopsy (EMB) data. b) A normal ECG excludes myocarditis. c) Serum biomarkers — such as CK, CK-MB and troponin — are not specific for myocarditis. d) Normal leukocytes and CRP values do not rule out an acute myocardial infla mmatory process. 9. Which THREE statements regarding the diagnosis of myocarditis are correct? a) CMR provides the most comprehensive and accurate information regarding functional abnormality, morphological changes and tissue characterisation. b) Endomyocardial biopsy is helpful in establishing the diagnosis, treatment options and prognosis in a range of conditions. c) Coronary artery disease must always be excluded before performing EMB. d) Patients undergoing EMB are at risk of complications, with the overall complication rate reported as less than 3% in most case series. 10. Which TWO statements regarding the management of myocarditis are correct? a) Unless ECG changes are present, all patients with suspected myocarditis can be safely investigated as outpatients. b) Mechanical circulatory support has not been shown to be of benefit in patients with fulminant myocarditis. c) Because of the high incidence of left ventricular dysfunction, standard heart failure regimens should be initiated, according to current guidelines. d) It is strongly recommended that patients with myocarditis avoid any competitive and leisure-time sport activity for six months. CPD POINTS CPD and PD points Each How to Treat has been allocated 2 RACGP QI&CPD points and 1 ACRRM point. OUT NOW! HT T y b Co v e r 1 6 Order the 2016 yearbook online. Hard copy and ebook available. See: http://bit.ly/2tjVZti 1 2 0 1 6 - 0 8 - 0 5 T1 1 : 1 5 : 2 4 + 1 0 : 0 0 Make sure you’re up-to-date with the latest assessment and diagnosis techniques as well as treatments with the 2015 How to Treat Yearbook. Order today from $99 hardcover and $79 eBook How to Treat yearbook - RACGP points are uploaded every six weeks and ACRRM PD points are uploaded quarterly. NEXT WEEK’S HOW TO TREAT 2016 YEARBOOK How to Treat Australia’s leading series on primary care treatment 2016 YEARBOOK OVER-THE-COUNTER CODEINE USE: The author is Dr Hester Wilson, NSW. latest editioN www.australiandoctor.com.au/httyb or call 1300 360 126 HOW TO TREAT Editor: Dr Claire Berman Email: [email protected] 26 | Australian Doctor | 7 July 2017 www.australiandoctor.com.au