of acm. since acm is an autosomal dominant trait, children of an acm patient have a 50% chance of inheriting the disease-causing mutation. whenever a mutation is identified by genetic testing, family-specific genetic testing can be used to differentiate between relatives who are at-risk for the disease and those who are not. acm genetic testing is clinically available. diagnostic criteria there is no pathognomonic feature of acm. the diagnosis of acm is based on a combination of major and minor criteria. to make a diagnosis of acm requires either 2 major criteria or 1 major and 2 minor criteria or 4 minor criteria. major criteria right ventricular dysfunction severe dilatation and reduction of rv ejection fraction with little or no lv impairment localized rv aneurysms severe segmental dilatation of the rv tissue characterization fibrofatty replacement of myocardium on endomyocardial biopsy electrocardiographical abnormalities epsilon waves in v1 – v3 localized prolongation (>110 ms) of qrs in v1 – v3 inverted t waves in v1 -v3 in an individual over 12 years old, in the absence of a right bundle branch block (rbbb) ventricular tachycardia with a left bundle branch block (lbbb) morphology, with superior axis family history familial disease confirmed either clinically or on autopsy or surgery minor criteria right ventricular dysfunction mild global rv dilatation and/or reduced ejection fraction with normal lv. mild segmental dilatation of the rv regional rv hypokinesis tissue characterization electrocardiographical abnormalities late potentials on signal averaged ekg. ventricular tachycardia with a left bundle branch block (lbbb) morphology, with inferior or unknown axis frequent pvcs (> 500 pvcs / 24 hours) management the goal of management of acm is to decrease the incidence of sudden cardiac death. this raises a clinical dilemma: how to prophylactically treat the asymptomatic patient who was diagnosed during family screening. a certain subgroup of individuals with acm are considered at high risk for sudden cardiac death. associated characteristics include: young age competitive sports activity malignant familial history extensive rv disease with decreased right ventricular ejection fraction. left ventricular involvement syncope episode of ventricular arrhythmia management options include pharmacological, surgical, catheter ablation, and placement of an implantable cardioverter-defibrillator. prior to the decision of the treatment option, programmed electrical stimulation in the electrophysiology laboratory may be performed for additional prognostic information. goals of programmed stimulation include: assessment of the disease's arrhythmogenic potential evaluate the hemodynamic consequences of sustained vt determine whether the vt can be interrupted via antitachycardia pacing (atp). regardless of the management option chosen, the individual is typically advised to undergo lifestyle modification, including avoidance of strenuous exercise, cardiac stimulants (i.e.: caffeine, nicotine, pseudoephedrine) and alcohol. regarding physical activity and exercise, arvc patients, as well as gene carriers of pathogenic arvc-associated desmosomal mutations, should not participate in competitive sports. these patients should be advised to limit their exercise programmes to leisure-time activities and remain under clinical surveillance. medications pharmacologic management of acm involves arrhythmia suppression and prevention of thrombus formation. sotalol, a beta blocker and a class iii antiarrhythmic agent, is the most effective antiarrhythmic agent in acm. other antiarrhythmic agents used include amiodarone and conventional beta blockers (i.e.: metoprolol). if antiarrhythmic agents are used, their efficacy should be guided by series ambulatory holter monitoring, to show a reduction in arrhythmic events. while angiotensin converting enzyme inhibitors (ace inhibitors) are well known for slowing progression in other cardiomyopathies, they have not been proven to be helpful in acm. individuals with decreased rv ejection fraction with dyskinetic portions of the right ventricle may benefit from long term anticoagulation with warfarin to prevent thrombus formation and subsequent pulmonary embolism. catheter ablation catheter ablation may be used to treat intractable ventricular tachycardia. it has a 60–90% success rate. unfortunately, due to the progressive nature of the disease, recurrence is common (60% recurrence rate), with the creation of new arrhythmogenic foci. indications for catheter ablation include drug-refractory vt and frequent recurrence of vt after icd placement, causing frequent discharges of the icd. implantable cardioverter-defibrillator an icd is the most effective prevention against sudden cardiac death. due to the prohibitive cost of icds, they are not routinely placed in all individuals with acm. indications for icd placement in the setting of acm include: cardiac arrest due to vt or vf symptomatic vt that is not inducible during programmed stimulation failed programmed stimulation-guided drug therapy severe rv involvement with poor tolerance of vt sudden death of immediate family member since icds are typically placed via a transvenous approach into the right ventricle, there are complications associated with icd placement and follow-up. due to the extreme thinning of the rv free wall, it is possible to perforate the rv during implantation, potentially causing pericardial tamponade. because of this, every attempt is made at placing the defibrillator lead on the ventricular septum. after a successful implantation, the progressive nature of the disease may lead to fibro-fatty replacement of the myocardium at the site of lead placement. this may lead to undersensing of the individual's electrical activity (potentially causing inability to sense vt or vf), and inability to pace the ventricle. heart transplant heart transplant may be performed in acm. it may be indicated if the arrhythmias associated with the disease are uncontrollable or if there is severe bi-ventricular heart failure that is not manageable with pharmacological therapy. family screening all first degree family members of the affected individual should be screened for acm. this is used to establish the pattern of inheritance. screening should begin during the teenage years unless otherwise indicated. screening tests include: echocardiogram ekg signal averaged ekg holter monitoring cardiac mri exercise stress test prognosis there is a long asymptomatic lead-time in individuals with acm. while this is a genetically transmitted disease, individuals in their teens may not have any characteristics of acm on screening tests. many individuals have symptoms associated with ventricular tachycardia, such as palpitations, light-headedness, or syncope. others may have symptoms and signs related to right ventricular failure, such as lower extremity edema, or liver congestion with elevated hepatic enzymes. acm is a progressive disease. over time, the right ventricle becomes more involved, leading to right ventricular failure. the right ventricle will fail before there is left ventricular dysfunction. however, by the time the individual has signs of overt right ventricular failure, there will be histological involvement of the left ventricle. eventually, the left ventricle will also become involved, leading to bi-ventricular failure. signs and symptoms of left ventricular failure may become evident, including congestive heart failure, atrial fibrillation, and an increased incidence of thromboembolic events. epidemiology the prevalence of acm is about 1/10,000 in the general population in the united states, although some studies have suggested that it may be as common as 1/1,000. recently, 1/200 were found to be carriers of mutations that predispose to acm. based on these findings and other evidence, it is thought that in most patients, additional factors such as other genes, athletic lifestyle, exposure to certain viruses, etc. may be required for a patient to eventually develop signs and symptoms of acm. it accounts for up to 17% of all sudden cardiac deaths in the young. in italy, the prevalence is 40/10,000, making it the most common cause of sudden cardiac death in the young population. society and culture notable cases columbus crew midfielder kirk urso collapsed out with friends on august 5, 2012, and was pronounced dead an hour later. an autopsy later revealed the disease to be the likely culprit. sevilla fc and spanish international left wing-back antonio puerta died from the condition, at the age of 22, on 28 august 2007, three days after suffering several cardiac arrests, while disputing a la liga game against getafe cf. englishman matt gadsby also died from the condition after collapsing on the pitch on 9 september 2006, while playing for hinckley united in a conference north game against harrogate town. suzanne crough, an american child actress best known for her role on the partridge family, died suddenly from the condition in 2015 at age 52. james taylor english international cricketer, retired april 2016. krissy taylor, an american model, died at the age of 17 on july 2, 1995, in the family home in florida. her official cause of death was cardiac arrhythmia and severe asthma, the latter of which she had never been diagnosed with. her family had independent experts examine tissue samples of her heart muscle and they concluded that the most likely cause of death was a missed diagnosis of acm. jordan boyd (1997-2013), canadian junior hockey player. he was posthumously diagnosed with the ailment after passing away from a collapse from training camp in 2013.