Prognostic impact of the findings of the genetic test in left dominant arrhythmogenic cardiomyopathy.

Background: The diagnosis of left dominant arrhythmogenic cardiomyopathy (LDAC) is sometimes complex. The Padua group recently published a document with criteria to identify patients with LDAC, requiring a compatible genetic variant for diagnosis. Due to the gaps in the knowledge of the role of genetics in its pathogenesis, our objective is to describe the findings of the genetic test in patients with LDAC in our center and its prognostic impact. Methods: Single-center prospective cohort study, in which we recruited 77 patients diagnosed with LDAC or biventricular arrhythmogenic cardiomyopathy according to the criteria of Sen-Chowdhry et al. Results: We obtained a positive result in the genetic test in 53.2 %. The desmoplakin gene was the most affected (16.9 %). The mean value of left ventricular (LV) ejection fraction was 45.6 ± 13.1 %, with no significant differences in the severity of the dysfunction according to genetics (p = 0.187). Among the patients with positive genetics there was a greater number of segments in the LV affected by fibrosis (p = 0.043). Regarding fatty infiltration in the LV and number of affected segments, there were no significant differences between groups (p = 0.144). MACE was recorded in 23 patients (29.9 %). The positive result in the genetic test was not significantly associated with the occurrence of MACE (p = 0.902). Conclusion: In our study, we did not find mutations responsible for the disease in practically half of the cases. Despite the existence of a high proportion of MACE during follow-up, there were no prognostic differences according to the result of the genetic test.

Cardiac magnetic resonance parameters associated with successful conversion from a single ventricular to a one-and-a-half or biventricular circulation in patients with a hypoplastic right ventricle.

BACKGROUND: Some patients with pulmonary atresia with an intact ventricular septum (PA/IVS) or a left ventricle dominant atrioventricular canal defect (LDAVC) with a hypoplastic right ventricle (RV) and univentricular (1 V) circulation may be candidates for conversion to either a complete biventricular (2 V) repair or a one-and-a-half ventricle repair (1.5 V). We sought to identify pre-operative cardiovascular magnetic resonance (CMR) findings associated with successful conversion from 1V to 1.5V or 2V circulation. METHODS: In this single center retrospective study, subjects with PA/IVS or LDAVC and no conotruncal abnormalities were included if they had a 1 V circulation at the time of CMR followed by a surgical intervention intended to convert them to a 1.5 V or 2 V circulation. Conversion failure was defined as any of the following: (1) oxygen saturation < 90% at the most recent follow-up, (2) conversion back to a 1.5 V or 1 V circulation, or (3) death. RESULTS: In the PA/IVS cohort (n = 15, median age 1.32 years), 10 patients underwent surgical conversion to a 1.5 V circulation and 5 to a 2 V circulation. In the attempted 1.5 V group, there were 2 failures, and these cases had a lower RV mass (p = 0.04). In the attempted 2 V group, there was 1 failure, and no CMR parameters were significantly different compared to the successes. Among the successful 2 V group patients, the minimum RV end-diastolic volume (EDV) was 27 ml/m2. In the LDAVC cohort (n = 15, median age 1.0 years), 1 patient underwent surgical conversion to a 1.5 V circulation and 14 patients to a 2 V circulation. In the attempted 1.5 V group, the 1 conversion was a failure and had an RV EDV of 15 ml/m2. In the attempted 2 V group, there were 2 failures, and these cases had a smaller RV:LV stroke volume ratio (p = 0.05) and a lower RV ejection fraction (p = 0.05) compared to the successes. Among the successful 2 V group patients, the minimum RV EDV was 22 ml/m2. CONCLUSIONS: We identified multiple CMR parameters associated with successful conversion from 1 V circulation to 1.5 V or 2 V circulation in patients with PA/IVS and LDAVC. This information may improve patient selection for conversion procedures and encourage larger studies to better define the role of CMR.

Left-dominant arrhythmogenic cardiomyopathy due to desmoplakin mutation: a case report.

The case of a 49-year-old man with acute onset of heart failure is presented. The initial work-up showed a dilated cardiomyopathy with severely reduced left ventricular ejection fraction. In the differential diagnostic process, hypertensive, ischaemic, and valvular aetiologies were discarded. Subsequently, a cardiac magnetic resonance revealed global hypokinesis and inferior and anterior subepicardial fibrosis. Once differential diagnoses of subepicardial fibrosis (myocarditis, sarcoidosis, and Chagas disease) were discarded, a genetic panel was performed, resulting in a heterozygous mutation of desmoplakin (DSP) gene c.6697_6698del. A left-dominant DSP arrhythmogenic cardiomyopathy mutation was diagnosed. Structural myocardial abnormalities and ventricular arrhythmias characterize arrhythmogenic cardiomyopathy. Up to 50% of cases are associated with mutations in DSP genes (JUP, DSP, and PKP2). DSP is the fundamental component of the desmosome structure and provides structural support through intercellular adhesion. Therefore, when frequent differential diagnoses are discarded, genetic studies for dilated cardiomyopathy and DSP mutation should be considered.

Diagnostic delay in arrhythmogenic cardiomyopathy.

AIMS: Diagnosis of arrhythmogenic cardiomyopathy (ACM) may be challenging, as it comprises diverse phenotypes (right dominant, biventricular, and left dominant), and each may overlap with other clinical entities. The issue of differential diagnosis with conditions mimicking ACM has been previously highlighted; however, a systematic analysis of ACM diagnostic delay, and of its clinical implications, is lacking. METHODS AND RESULTS: Data of all ACM patients from three Italian Cardiomyopathy Referral Centres were reviewed to assess the time from first medical contact to definitive ACM diagnosis; a significant diagnostic delay was defined as a time to ACM diagnosis ≥2 years. Baseline characteristics and clinical course of patients with and without diagnostic delay were compared. Of 174 ACM patients, 31% experienced diagnostic delay, with a median time to diagnosis of 8 years (20% in right-dominant ACM, 33% in left-dominant ACM, and 39% in biventricular). Patients with diagnostic delay, when compared with those without, more frequently exhibited an ACM phenotype with left ventricular (LV) involvement (74 vs. 57%, P = 0.04) and a specific genetic background (none had plakophilin-2 variants). The most common initial (mis)diagnoses were dilated cardiomyopathy (51%), myocarditis (21%), and idiopathic ventricular arrhythmia (9%). At follow-up, all-cause mortality was greater in those with diagnostic delay (P = 0.03). CONCLUSION: Diagnostic delay is common in patients with ACM, particularly in the presence of LV involvement, and is associated with greater mortality at follow-up. Clinical suspicion and increasing use of tissue characterization by cardiac magnetic resonance in specific clinical settings are of key importance for the timely identification of ACM.

Almost one-third of patients with arrhythmogenic cardiomyopathy (ACM) experience a diagnostic delay >2 years. These patients are mostly affected by an ACM phenotype with left ventricular (LV) involvement and present worse mortality compared with those without diagnostic delay.Diagnostic delay is common in patients with ACM, particularly in the presence of LV involvement, and is associated with greater mortality at follow-up.The most common initial (mis)diagnoses were dilated cardiomyopathy, myocarditis, and idiopathic ventricular arrhythmia. Clinical suspicion and increasing use of tissue characterization by cardiac magnetic resonance in these specific clinical settings are of key importance to identify ACM in a timely fashion.

Role of cardiac magnetic resonance in the differential diagnosis between arrhythmogenic cardiomyopathy with left ventricular involvement and previous infectious myocarditis.

AIMS: Arrhythmogenic cardiomyopathy with left ventricular involvement (ACM-LV), particularly in case of isolated left ventricular involvement (i.e. left dominant arrhythmogenic cardiomyopathy, LDAC) and previous infectious myocarditis (pIM) may have overlapping clinical and cardiac magnetic resonance (CMR) features. To date, there are no validated CMR criteria for the differential diagnosis between these conditions. The present study aimed to identify CMR characteristics to distinguish ACM-LV from pIM. METHODS AND RESULTS: This observational, retrospective, single-centre study included 30 pIM patients and 30 ACM-LV patients. In ACM-LV patients CMR was performed at diagnosis; in patients with pIM, CMR was performed six months after acute infection. CMR analysis included quantitative assessment of left ventricle (LV) volumes, systolic function and wall thicknesses, qualitative and quantitative assessment of late gadolinium enhancement (LGE) sequences. Compared with pIM, ACM-LV patients showed slightly larger LV volumes, more frequent regional wall motion anomalies and reduced wall thicknesses. ACM-LV patients had higher amounts of LV LGE and extension. Notably, the LDAC subgroup had the highest amount of LV LGE. LV LGE amount > 15 g and a LV LGE percentage > 30% of LV mass discriminated ACM-LV from pIM with a 100% specificity. LGE segmental distribution was superimposable among the groups, except for septal segments that were more frequently involved in ACM-LV and LDAC patients. CONCLUSIONS: A great extension of LV LGE (a cut-off of LGE >15 g and a percentage above 30% of LV LGE in relation to total myocardial mass) discriminates ACM-LV from pIM with extremely high specificity.

Left-dominant arrhythmogenic cardiomyopathy in a Fila Brasileiro dog.

Background: In human medicine, arrhythmogenic left ventricular cardiomyopathy was described as a primary disease of the heart characterized by fibroadipose replacement of the myocardium.. Case Description: We report the case of a dog, with history of syncope and irregular cardiac rhythm. Electrocardiogram, echocardiography, and a 24-hour Holter monitoring showed, respectively, the presence of premature ventricular complexes with right bundle branch block morphology, an increase of the left ventricle end-diastolic diameter with preserved fractional shortening and ejection fraction, and a sinus arrhythmia as baseline rhythm with supraventricular tachycardia episodes and ventricular complexes with left bundle branch block morphology. After the death of the canine, a postmortem examination showed cardiomegaly. Fibroadipose replacement of the septum and both ventricles, with left ventricle myocardial fibrosis, suggestive of previous necrosis, was observed. Conclusion: These findings are suggestive of left-dominant arrhythmogenic cardiomyopathy which, to the best of our knowledge, has not been described in veterinary medicine.

Dilated left ventricle with multiple outpouchings - a severe congenital ventricular diverticulum or left-dominant arrhythmogenic cardiomyopathy: A case report.

BACKGROUND: Left-dominant arrhythmogenic cardiomyopathy (LDAC) is a relatively rare disease characterized by poor prognosis that exacerbates the incidence of sudden cardiac death and ventricular arrhythmias. Clinically, LDAC is constantly overlooked or misdiagnosed as myocardial infarction, myocarditis, and dilated cardiomyopathy, owing to atypical and nonspecific clinical manifestations at an early stage. CASE SUMMARY: A 57-year-old woman was diagnosed with sinus bradycardia and chronic bifascicular block during a health check. She occasionally experienced mild chest pain and paroxysmal palpitation during activity in the past 2 years. Comprehensive auxiliary examinations, including electrocardiogram, echocardiography, coronary computerized tomography angiography, and magnetic resonance imaging, revealed that she had LDAC instead of congenital ventricular diverticulum. The physicians prescribed standard oral therapy for heart failure and implantable cardioverter-defibrillator. Consequently, her left ventricular systolic function and symptoms remained stable at the 2-year follow-up after discharge. CONCLUSION: Based on this case, clinicians need to be aware of LDAC in patients with localized left ventricular lesions and multiple electrocardiographic abnormalities. Multimodality cardiovascular imaging is effective in identification of multiple types of cardiomyopathy and cardiac inner structures.

A case series of desmoplakin cardiomyopathy: a mimic of viral myocarditis.

Background: Clinical features and imaging presentation of myocarditis can overlap with other inflammatory or arrhythmogenic cardiomyopathies. Desmoplakin (DSP) is an important structural cardiac protein. Mutations in the DSP gene are associated with a variant of arrhythmogenic right ventricular cardiomyopathy (ARVC). Interestingly, this distinct genetic cardiomyopathy can also present with a myocardial inflammation and fibrosis pattern that may mimic other forms of myocarditis including viral myocarditis, which can raise a clinical challenge. We report two cases of DSP cardiomyopathy, which were initially thought to represent coronavirus disease of 2019 (COVID-19) myocarditis. Case summary: First patient is a 21-your-old woman with no past medical history but family history of presumed 'viral myocarditis' and ventricular tachycardia in her brother. She presented with acute chest pain and elevated cardiac enzymes. She tested positive for COVID-19 and given the suspicion for possible COVID-19 related acute myocarditis, cardiac magnetic resonance imaging obtained and revealed regional wall motion abnormalities, several areas of subepicardial and pericardial late gadolinium enhancement (LGE). Ambulatory cardiac monitoring showed runs of non-sustained ventricular tachycardia and considering her family history of arrhythmogenic myocarditis, genetic testing was performed that was positive for a likely pathogenic heterozygous mutation of DSP gene. She declined the recommended implantable cardioverter defibrillator (ICD).Second patient is a 34-year-old physician with no significant past medical history who works at a COVID-19 unit and presented with syncope and was found to have ventricular tachycardia. Echocardiogram revealed severely dilated left ventricle and globally depressed systolic function with left ventricular ejection fraction of 20%. Coronary computed tomography angiography showed no evidence of coronary atherosclerosis. Cardiac magnetic resonance imaging revealed several areas of mid myocardial and pericardial LGE. Subcutaneous ICD was implanted and an endomyocardial biopsy had evidence of lymphocytic myocarditis and adipose tissue infiltration of the myocardium. Genetic testing revealed pathogenic heterozygous DSP mutation. He underwent epicardial ablation for the episodes of ventricular tachycardia despite medical therapy. He was able to return to work and has not had any further episodes of arrhythmia. Conclusion: Mutations in the DSP gene are associated with left dominant arrhythmogenic cardiomyopathy, which is a variant of ARVC. Beside left ventricular systolic dysfunction and ventricular tachyarrhythmias, carriers of these mutations may present with episodes of chest pain associated with elevated cardiac enzymes and cardiac imaging findings indistinguishable from other forms of acute myocarditis including viral myocarditis. Currently, there are no guidelines for diagnosis and treatment of this entity.

Cardiac magnetic resonance features of left dominant arrhythmogenic cardiomyopathy: differential diagnosis with myocarditis.

Cardiac magnetic resonance (CMR) findings suggesting a suspected left-dominant arrhythmogenic cardiomyopathy (LDAC) may be difficult to distinguish from those related to previous myocarditis; however, especially in patients with ventricular arrhythmias (VA) with ECG morphology consistent with a left ventricle (LV) origin differential diagnosis is fundamental. Aim of the study was to identify potential imaging features at CMR specific for LDAC diagnosis. Between January 2011 and December 2019, we enrolled 15 consecutive stable patients with a recent diagnosis of significant VA and ECG morphology consistent with a LV origin, detection of potential LV arrhythmic substrate at CMR and undergoing a clinically-indicated LV endomyocardial biopsy showing tissue abnormalities consistent with the diagnosis of LDAC. From the same CMR-endomyocardial biopsy registry, a second group of 30 consecutive patients who underwent CMR and biopsy with a histological diagnosis of previous myocarditis were identified. (1) Subepicardial LGE at the level of the posterolateral wall of the LV was detected in 13 cases of LDAC vs. 21 cases of myocarditis; (2) fat infiltration, and particularly subepicardial posterolateral fat infiltration, was found in almost all LDAC patients vs. one myocarditis only (p < 0.01). (3) No differences in other CMR findings or in any clinical or echocardiographic parameters were found between patients with a biopsy consistent with LDAC vs. myocarditis. In patients with significant VA and ECG morphology consistent with a LV origin, the presence of morpho-functional involvement of the subepicardial layer of LV posterolateral wall at CMR (LGE, fat infiltration, wall dyskinesis) supports LDAC diagnosis.

Left-dominant arrhythmogenic cardiomyopathy: an association with desmoglein-2 gene mutation-a case report.

BACKGROUND: Desmosomes are specialized intercellular adhesive junctions of cardiac and epithelial cells that provide intercellular mechanical coupling through glycoproteins, one of which is desmoglein (DSG). DSG-2 mutations are frequently associated with biventricular arrhythmogenic cardiomyopathy (ACM). We report a case of left-dominant ACM in a patient who initially was misclassified as dilated cardiomyopathy (DCM). CASE SUMMARY: A 28-year-old-woman was found to have a moderately reduced left ventricular (LV) systolic function and frequent premature ventricular contractions (PVCs). Targeted genetic testing revealed a heterozygous likely pathogenic variant associated with ACM in exon 15 of the DSG-2 gene (c.3059_3062del; p.Glu1020Alafs*18). Subsequent cardiac magnetic resonance (CMR) imaging showed epicardial and mid-myocardial fatty infiltration involving multiple LV wall segments, multiple areas of mid-myocardial fibrosis/scar, regional dyskinesis involving both ventricles, and an overall reduced left ventricular ejection fraction. The patient's right ventricular (RV) cavity size and overall RV systolic function were normal. Based on the patient's frequent PVCs, family history, fibrofatty myocardial replacement in multiple LV segments, and dyskinetic motion of multiple ventricular wall segments (predominantly affecting the LV), the patient was diagnosed with left-dominant ACM. DISCUSSION: Identifying a likely pathogenic mutation associated with ACM in a patient with ventricular arrhythmias and a family history of sudden cardiac death increased the possibility of ACM. Subsequent CMR imaging confirmed the diagnosis of left-dominant ACM by demonstrating regional biventricular dyskinesia and a characteristic pattern of fibrofatty myocardial replacement. Our case highlights the importance of targeted genetic testing and advanced cardiac imaging in distinguishing left-dominant ACM from DCM.

Prognosis of Patients With Left Circumflex Artery Acute Myocardial Infarction in Relation to ST-Segment on Admission Electrocardiogram.

BACKGROUND: Total thrombotic occlusion of the left circumflex (LCX) artery may present without ST-segment elevations; the clinical outcomes of such patients remain unclear. OBJECTIVE: To examine the difference in clinical outcomes between patients with acute myocardial infarction (MI) due to LCX occlusion or stenosis with and without ST-segment elevation. METHODS: The present study is based on an observational, retrospective cohort comprising all patients admitted to 2 centers between 2009 and 2019 with MI due to LCX disease. Clinical outcomes included recurrent percutaneous coronary intervention (PCI), hospitalization due to acute coronary syndrome (ACS), and mortality. Risk factors for mortality were assessed using logistic regression analysis. RESULTS: During the study period, a total of 897 patients with LCX-related MI were treated. Most (56.6%) presented with non-ST segment elevation MI (NSTEMI), which was associated with higher rates of 1-year hospitalization for ACS (15.8% vs 11.1%; P=.05) and PCI (20.9% vs 14.4%; P=.05) compared with ST-segment elevation MI (STEMI) patients. STEMI was associated with higher 30-day mortality compared with NSTEMI (3.9% vs 1.7%, respectively; P=.05), with no difference in mortality after 1 year (6.7% vs 5.6%, respectively; P=.55). Multivariate analysis found left dominant circulation (odds ratio [OR], 2.62; 95% confidence interval [CI], 1.4-4.7) and diabetes mellitus (OR, 2.13; 95% CI, 1.2-3.6) to be independent predictors for 1-year mortality. CONCLUSION: Patients suffering from NSTEMI and STEMI related to LCX occlusion or stenosis have similar 1-year mortality. Left dominant circulation was associated with higher short- and long-term mortality. These results suggest that a substantial population of patients who present as NSTEMI should be treated as promptly and aggressively as STEMI patients.

Emerging concepts in arrhythmogenic dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) represents one of the primary cardiomyopathies and may lead to heart failure and sudden death. Until recently, ventricular arrhythmias were considered to be a direct consequence of the systolic dysfunction of the left ventricle (LV) and guidelines for implantable cardioverter defibrillator implantation were established on this basis. However, the identification of heritable dilated cardiomyopathy phenotypes that presented with mildly impaired or moderate LV dysfunction, with or without chamber dilatation, and ventricular arrhythmias exceeding the degree of the underlying morphological abnormalities lead to the identification of the arrhythmogenic phenotypes and genotypes of DCM. This subset of DCM patients presents phenotypic and in many cases genotypic overlaps with left dominant arrhythmogenic cardiomyopathy (LDAC). LMNA, SCN5A, FLNC, TTN, and RBM20 are the main genes responsible for arrhythmogenic DCM. Moreover, desmosomal genes such as DSP and other non-desmosomal such as DES and PLN have been associated with both LDAC and arrhythmogenic DCM. The aim of this review is to highlight the importance of genetic profiling among DCM patients with disproportionate arrhythmic burden and the significance of the electrocardiogram, cardiac magnetic resonance, Holter monitoring, detailed family history, and other assays in order to identify red flags for arrhythmogenic DCM and proceed to an early preventive approach for sudden cardiac death. A special consideration was given to the phenotypic and genotypic overlap with LDAC. The role of myocarditis as a common disease expression of LDAC and arrhythmogenic DCM is also analyzed supporting the premise of their phenotypic overlap.

Prognostic Value of Magnetic Resonance Phenotype in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Cardiac magnetic resonance (CMR) is widely used to assess tissue and functional abnormalities in arrhythmogenic right ventricular cardiomyopathy (ARVC). Recently, a ARVC risk score was proposed to predict the 5-year risk of malignant ventricular arrhythmias in patients with ARVC. However, CMR features such as fibrosis, fat infiltration, and left ventricular (LV) involvement were not considered. OBJECTIVES: The authors sought to evaluate the prognostic role of CMR phenotype in patients with definite ARVC and to evaluate the effectiveness of the novel 5-year ARVC risk score to predict cardiac events in different CMR presentations. METHODS: A total of 140 patients with definite ARVC were enrolled (mean age 42 ± 17 years, 97 males) in this multicenter prospective registry. As per study design, CMR was performed in all the patients at enrollment. The novel 5-year ARVC risk score was retrospectively calculated using the patient's characteristics at the time of enrollment. During a median follow-up of 5 years (2 to 8 years), the combined endpoint of sudden cardiac death, appropriate implantable cardioverter-defibrillator intervention, and aborted cardiac arrest was considered. RESULTS: CMR was completely negative in 14 patients (10%), isolated right ventricular (RV) involvement was found in 58 (41%), biventricular in 52 (37%), and LV dominant in 16 (12%). During the follow-up, 48 patients (34%) had major events, but none occurred in patients with negative CMR. At Kaplan-Meier analysis, patients with LV involvement (LV dominant and biventricular) had a worse prognosis than those with lone RV (p < 0.0001). At multivariate analysis, the LV involvement, a LV-dominant phenotype, and the 5-year ARVC risk score were independent predictors of major events. The estimated 5-year risk was able to predict the observed risk in patients with lone RV but underestimated the risk in those with LV involvement. CONCLUSIONS: Different CMR presentations of ARVC are associated with different prognoses. The 5-year ARVC risk score is valid for the estimation of risk in patients with lone-RV presentation but underestimated the risk when LV is involved.

Left-dominant arrhythmogenic cardiomyopathy with a nonsense mutation in DSP.

A 74-year-old man had abnormal left ventricular (LV) function according to a perioperative test at a local hospital and was transferred to our institution for further evaluation and treatment. His electrocardiogram demonstrated the presence of premature ventricular contraction with a QRS complex of the right bundle branch block type and superior axis. His echocardiography showed systolic dysfunction of the LV (LV ejection fraction, 44.6%). Cardiac computed tomography imaging revealed banded and patchy densities observed frequently from the middle to epicardial layer of the LV wall. Cardiac magnetic resonance imaging showed fat signals on fat-selective images and late gadolinium enhancement in the mid-wall to subepicardial layers in the LV myocardium. Endomyocardial biopsy revealed the histological presence of fibrofatty replacement. A genetic analysis revealed a nonsense mutation in the desmoplakin gene. Thus, he was diagnosed with left-dominant arrhythmogenic cardiomyopathy. To prevent fatal ventricular arrhythmias, an implantable cardioverter defibrillator was successfully implanted.

Long-term follow-up analysis of a highly characterized arrhythmogenic cardiomyopathy cohort with classical and non-classical phenotypes-a real-world assessment of a novel prediction model: does the subtype really matter.

AIMS: To provide long-term outcome data on arrhythmogenic cardiomyopathy (ACM) patients with non-classical forms [left dominant ACM (LD-ACM) and biventricular ACM (Bi-ACM)] and an external validation of a recently proposed algorithm for ventricular arrhythmia (VA) prediction in ACM patients. METHODS AND RESULTS: Demographic, clinical, and outcome data were retrieved from all ACM patients encountered at our institution. Patients were classified according to disease phenotype (R-ACM; Bi-ACM; LD-ACM). Overall and by phenotype long-term survival were calculated; the novel Cadrin-Tourigny et al. algorithm was used to calculate the a priori predicted VA risk, and it was compared with the observed outcome to test its reliability. One hundred and one patients were enrolled; three subgroups were defined (R-ACM, n = 68; Bi-ACM, n = 14; LD-ACM, n = 19). Over a median of 5.41 (2.59-8.37) years, the non-classical form cohort experienced higher rates of VAs than the classical form [5-year freedom from VAs: 0.58 (0.43-0.78) vs. 0.76 (0.66-0.89), P = 0.04]. The Cadrin-Tourigny et al. predictive model adequately described the overall cohort risk [mean observed-predicted risk difference (O-PRD): +6.7 (-4.3, +17.7) %, P = 0.19]; strafing by subgroup, excellent goodness-of-fit was demonstrated for the R-ACM subgroup (mean O-PRD, P = 0.99), while in the Bi-ACM and LD-ACM ones the real observed risk appeared to be underestimated [mean O-PRD: -20.0 (-1.1, -38.9) %, P < 0.0001; -22.6 (-7.8, -37.5) %, P < 0.0001, respectively]. CONCLUSION: Non-classical ACM forms appear more prone to VAs than classical forms. The novel prediction model effectively predicted arrhythmic risk in the classical R-ACM cohort, but seemed to underestimate it in non-classical forms.

Importance of cardiac magnetic resonance findings in the diagnosis of left dominant arrythmogenic cardiomyopathy.

INTRODUCTION AND OBJECTIVES: Left dominant arrhythmogenic cardiomyopathy (LDAC) has recently been recognized as falling on the spectrum of arrhythmogenic cardiomyopathy. It is characterized by fibroadipose replacement of the left ventricle. The aim of this study was to describe the most frequent forms of clinical presentation of LDAC, imaging findings, and events at follow-up, highlighting the importance of cardiac magnetic resonance (CMR). METHODS: Prospective registry of patients with findings compatible with LDAC. CMR image analysis and clinical follow-up was performed. The primary endpoint was the appearance of major adverse cardiovascular events (MACE) during follow-up, defined as sudden cardiac death, sustained ventricular arrhythmias, and heart transplant. RESULTS: We included 74 consecutive patients (mean age, 48.6 years; 50 men [67.6%]). The most frequent CMR indications were chest pain with normal coronary angiography, ventricular arrhythmias, and suspicion of cardiomyopathies. The main CMR findings were midwall and/or subepicardial pattern of late gadolinium enhancement (91.9%), fatty epicardial infiltration (83.8%), and left ventricle segmental contractility abnormalities (47.9%). At a mean follow-up of 3.74 years, 24 patients (32.4%) had a MACE (sudden cardiac death 8.1%, sustained ventricular arrhythmias 21.6%, and heart transplant 4.1%). Independent predictors for the appearance for MACE were a CMR study showing severe late gadolinium enhancement, male sex, and practicing sports. CONCLUSIONS: CMR is a key tool for diagnosing LDAC. Characteristic findings are subepicardial fatty infiltration and midwall-subepicardial late gadolinium enhancement. The prognosis of this population is poor with a high incidence of sudden cardiac death and ventricular arrhythmias.

Preoperative functional magnetic resonance imaging in patients undergoing surgery for tumors around left (dominant) inferior frontal gyrus region.

BACKGROUND: Preoperative functional magnetic resonance imaging (fMRI) helps to preserve neurological function and ensure maximal tumor tissue excision. We studied the lateralization and localization of speech centers in select cases of tumors around the left (dominant) inferior frontal gyrus (IFG). METHODS: Twenty-three right-handed patients, harboring tumors involving the left (dominant) IFG or causing mass effect or edema extending onto the left IFG, were recruited over 17 months. Preoperatively, all patients underwent language and speech assessment followed by MRI and fMRI with paradigm (picture naming). Normative data for language fMRI was taken from the institute's imaging data bank. RESULTS: The study included 23 patients [mean age: 38.9 (±11.9) years; M: F = 16:7; 9 - normal speech, 14 - abnormal speech]. Group analysis of controls showed significant activation in the region of interest (ROI) - left Brodmann's areas (BAs) 44,45. Group analysis of patients with normal speech showed no activation in the left BAs 44,45; however, activation was noted in the immediate adjacent areas, left BAs 13,47 and contralateral prefrontal cortex. Group analysis of patients with impaired speech showed no activation in BAs 44,45 or in the immediate adjacent areas. CONCLUSIONS: Neuroplasticity in the brain may enable functional language areas to shift to adjoining or distant regions in the brain when the primary areas are involved by intrinsic tumors. This phenomenon is more likely in slow-growing compared to fast-growing tumors. Preoperative language fMRI may help us in identifying and protecting these areas during surgery.

Accuracy of exercise tolerance test in the diagnosis of coronary artery disease in patients with left dominant coronary circulation.

BACKGROUND: Exercise is a physiologic stress that helps the physicians to clarify the presence or absence of cardiovascular disease which may be obscure at rest. Although it is sensitive, its specificity is affected by several parameters, such as some metabolic conditions, some structural heart diseases, and some baseline electrocardiogram abnormalities. Currently, the relationship between coronary dominance and accuracy of EET is not examined. Therefore, this study was conducted to determine the potential impact of coronary dominance on the accuracy of EET. METHODS: In this retrospective study, data were gathered from 720 patients from four medical centers. The pattern of dominancy was determined, and the coronary dominance pattern of the patients who had normal angiograms despite abnormal EETs was compared to that from all the patients. RESULTS: Among the patients who had a normal angiogram despite an abnormal EET, 27% were left dominant while the frequency of left dominancy in the whole population of the study was only 10.9% (P=0.013). There were no significant differences in baseline characteristics, such as age and sex, between the two studied groups. CONCLUSION: The results indicated that the presence of left dominance in patients who had normal angiograms despite an abnormal EET was significantly higher than general population. Therefore, left dominance may be considered a confounding factor for EET, producing false positive results.