The great deceiver: a case series of 'double fire' atrioventricular nodal response.

Background: The 'double fire' (DF) atrioventricular (AV) nodal response is a rare mechanism of two ventricular electrical activations following a single atrial beat due to dual AV node physiology. DF AV nodal response is often misdiagnosed and may lead to unnecessary invasive procedures. Case summary: We describe a series of three cases with distinct clinical manifestations of DF AV nodal response: Patient 1 remained symptomatic after slow pathway modification for common AV nodal re-entry tachycardia. Patient 2 was misdiagnosed as having junctional bigeminy and developed heart failure with reduced left ventricle ejection fraction. Patient 3 was misdiagnosed as having atrial fibrillation (AF) and underwent two pulmonary vein isolation (PVI) procedures, without clinical improvement. All patients underwent an electrophysiological study (EPS) during which DF AV nodal response was confirmed and treated with radiofrequency ablation of the slow pathway. All patients were afterwards relieved from their symptoms. Discussion and conclusion: DF AV nodal response is a rare electrophysiological phenomenon which can be clinically misinterpreted as other common arrhythmias, such as premature junctional bigeminy or AF and can contribute to tachycardia induced cardiomyopathy. Typical electrocardiogram- and EPS-derived findings can be indicative for DF AV nodal response. DF AV nodal response can be easily and effectively treated by slow pathway ablation.

Left atrial volume index: Can it provide additional prognostic information in ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention?

INTRODUCTION: We sought to assess the prognostic impact of left atrial (LA) size on long-term outcomes of ST-segment elevation myocardial infarction (STEMI). METHODS: We studied 200 consecutive patients admitted to a single center between January 2010 and December 2014 with non-fatal STEMI treated with primary percutaneous coronary intervention (pPCI) who underwent a comprehensive echocardiographic examination at discharge. LA volume was estimated by the area-length method. The left atrium was classified as normal, mildly, moderately or severely enlarged by LA volume index (LAVI). The endpoints were defined as all-cause mortality, a cardiac composite endpoint (all-cause mortality, reinfarction, unplanned revascularization and hospitalization for heart failure) and a cardiovascular composite endpoint (cardiac endpoint plus atrial fibrillation and ischemic stroke) during follow-up. RESULTS: In this STEMI population, 58% had normal LA size, 22.5% had mild LA enlargement, 10% had moderate LA enlargement and 9.5% had severe LA enlargement. During a median follow-up of 28 (IQR 21-38) months, 14 (7.0%) patients died, 53 (26.5%) had the cardiac and 58 (29%) the cardiovascular composite endpoints. There was a stepwise increase in the incidence of all-cause mortality (p=0.020) and both cardiac (p<0.001) and cardiovascular (p<0.001) endpoints with each increment of LAVI class. In multivariate analysis, severe LA enlargement by LAVI was an independent predictor of all-cause mortality (HR: 11.153; 95% CI: 1.924-64.642, p=0.007) and the cardiac (HR: 4.351; 95% CI: 1.919-9.862, p<0.001) and cardiovascular (HR: 4.351; 95% CI: 1.919-9.862, p<0.001) endpoints during follow-up. CONCLUSIONS: This contemporary study confirms the prognostic effect of LA size at discharge, applying the most recent reference values in STEMI patients treated with pPCI.

Short-term prognostic effect of prior cerebrovascular and peripheral artery disease in patients with acute coronary syndrome: Can we do better?

BACKGROUND: We sought to evaluate the impact of prior cerebrovascular and/or peripheral arterial disease (PAD) on in-hospital outcomes in patients with acute coronary syndromes. METHODS: From 1 October 2010 to 26 February 2016, 13,904 acute coronary syndrome patients were enrolled in a national multicentre registry. They were divided into four groups: prior stroke/transient ischaemic attack (stroke/TIA); prior PAD; prior stroke/TIA and PAD; none. The endpoints included in-hospital mortality and a composite endpoint of death, re-infarction and stroke during hospitalization. RESULTS: 6.3% patients had prior stroke/TIA, 4.2% prior PAD and 1.4% prior stroke/TIA and PAD. Prior stroke/TIA and/or PAD patients were less likely to receive evidence-based medical therapies (dual antiplatelet therapy: stroke/TIA= 88.6%, PAD= 86.6%, stroke/TIA+PAD= 85.7%, none= 92.2%, p<0.001; ß-blockers: stroke/TIA= 77.1%, PAD= 72.1%, stroke/TIA+PAD= 71.9%, none= 80.8%, p<0.001; angiotensin-converting enzyme inhibitors/angiotensin receptor blockers: stroke/TIA= 86.3%, PAD= 83.6%, stroke/TIA+PAD= 83.2%, none= 87.1%, p=0.030) and to undergo percutaneous revascularization (stroke/TIA= 52.8%, PAD= 45.6%, stroke/TIA+PAD= 43.7%, none= 67.9%, p<0.001), despite more extensive coronary artery disease (three-vessel disease: stroke/TIA= 29.1%, PAD= 38.3%, stroke/TIA+PAD= 38.3%, none= 20.2%, p<0.001). In a multivariable analysis, prior stroke/TIA+PAD was a predictor of in-hospital mortality (odds ratio= 2.828, 95% confidence interval 1.001-7.990) and prior stroke/TIA (odds ratio= 1.529, 95% confidence interval 1.056-2.211), prior PAD (odds ratio= 1.618, 95% confidence interval 1.034-2.533) and both conditions (odds ratio= 3.736, 95% confidence interval 2.002-6.974) were associated with the composite endpoint. CONCLUSION: A prior history of stroke/TIA and/or PAD was associated with lower use of medical therapy and coronary revascularization and with worst short-term prognosis. An individualized management may improve their poor prognosis.

Relationship between treatment delay and type of reperfusion therapy and mechanical complications of acute myocardial infarction.

OBJECTIVES: The incidence of mechanical complications after acute myocardial infarction has markedly declined with the advent of reperfusion. Nevertheless there is some controversy about the equal effectiveness of the different reperfusion therapies in preventing these complications. We aimed to analyse how reperfusion therapy and treatment delay relate to the incidence of mechanical complications in a population of ST-elevation myocardial infarction (STEMI) patients. METHODS: We analysed all STEMI patients included in the second phase of the Portuguese Registry on Acute Coronary Syndromes, between October 2010 and July 2015. We compared both conservative medical treatment with reperfusion therapy and thrombolysis with primary percutaneous coronary intervention for mechanical complications. We also evaluated the impact of treatment delay on mechanical complications. RESULTS: Among 5230 STEMIs we observed 77 mechanical complications (1.5%). These were significantly more frequent in the non-reperfused patients (3.3% vs. 1.1%, P<0.001) and they were numerically higher in thrombolysis than in primary percutaneous coronary intervention patients (1.6% vs. 1.0%, respectively, P=0.282). Patients with mechanical complications had higher times from symptom onset to hospitalisation and to reperfusion. In multivariate analysis performing reperfusion therapy (odds ratio 0.52, 95% confidence interval 0.29-0.93) and a time from symptom onset to hospitalisation ⩾6 hours (odds ratio 2.44, 95% confidence interval 1.37-4.33) were independent predictors of mechanical complications. The type of reperfusion did not influence the occurrence of mechanical complications. CONCLUSION: A longer time from symptom onset to hospitalisation was associated with an increased number of mechanical complications. Timely reperfusion therapy prevented mechanical complications and no significant difference was found between thrombolysis and primary percutaneous coronary intervention.

Effect of Obstructive Sleep Apnea in Acute Coronary Syndrome.

The effect of obstructive sleep apnea (OSA) on clinical outcomes after acute coronary syndrome (ACS) is incompletely defined. We sought to determine the prevalence of OSA in patients with ACS and evaluate prognostic impact of OSA and continuous positive airway pressure (CPAP) therapy in these patients. This was a prospective longitudinal cohort study of 73 patients admitted on cardiac intensive care unit for ACS. Cardiorespiratory sleep study and/or polysomnography were performed in all patients. CPAP was recommended if Apnea-Hypopnea Index ≥5. The main study outcome was a composite of death for any cause, myocardial infarction, and myocardial revascularization. OSA was diagnosed in 46 patients (63%). Age and cardiovascular risk factors were not significantly different between groups. OSA was classified as mild (m-OSA) in 14 patients (30%) and as moderate-to-severe (s-OSA) in 32 patients (70%). After a median follow-up of 75 months (interquartile range 71 to 79), patients with s-OSA had lower event-free survival rate. After adjustment for gender, patients with s-OSA showed a significantly higher incidence of the composite end point (hazard ratio 3.58, 95% CI 1.09 to 17.73, p = 0.035). Adherence to CPAP occurred in 19 patients (41%), but compliance to CPAP therapy did not reduce the risk of composite end point (hazard ratio 0.87, 95% CI 0.31 to 2.46, p = 0.798). In conclusion, OSA is an underdiagnosed disease with high prevalence in patients with ACS. It is urgent to establish screening protocols because those have high diagnostic yield and allow identifying a group of patients with manifestly unfavorable prognosis.

Screening for Fabry disease in left ventricular hypertrophy: documentation of a novel mutation.

BACKGROUND: Fabry disease is a lysosomal storage disease caused by enzyme α-galactosidase A deficiency as a result of mutations in the GLA gene. Cardiac involvement is characterized by progressive left ventricular hypertrophy. OBJECTIVE: To estimate the prevalence of Fabry disease in a population with left ventricular hypertrophy. METHODS: The patients were assessed for the presence of left ventricular hypertrophy defined as a left ventricular mass index ≥ 96 g/m2 for women or ≥ 116 g/m2 for men. Severe aortic stenosis and arterial hypertension with mild left ventricular hypertrophy were exclusion criteria. All patients included were assessed for enzyme α-galactosidase A activity using dry spot testing. Genetic study was performed whenever the enzyme activity was decreased. RESULTS: A total of 47 patients with a mean left ventricular mass index of 141.1 g/m2 (± 28.5; 99.2 to 228.5 g/m2] were included. Most of the patients were females (51.1%). Nine (19.1%) showed decreased α-galactosidase A activity, but only one positive genetic test - [GLA] c.785G>T; p.W262L (exon 5), a mutation not previously described in the literature. This clinical investigation was able to establish the association between the mutation and the clinical presentation. CONCLUSION: In a population of patients with left ventricular hypertrophy, we documented a Fabry disease prevalence of 2.1%. This novel case was defined in the sequence of a mutation of unknown meaning in the GLA gene with further pathogenicity study. Thus, this study permitted the definition of a novel causal mutation for Fabry disease - [GLA] c.785G>T; p.W262L (exon 5).

Screening for Fabry Disease in Left Ventricular Hypertrophy: Documentation of a Novel Mutation / Rastreio de Doença de Fabry na Hipertrofia Ventricular Esquerda: Documentação de uma Nova Mutação

AbstractBackground:Fabry disease is a lysosomal storage disease caused by enzyme α-galactosidase A deficiency as a result of mutations in the GLA gene. Cardiac involvement is characterized by progressive left ventricular hypertrophy.Objective:To estimate the prevalence of Fabry disease in a population with left ventricular hypertrophy.Methods:The patients were assessed for the presence of left ventricular hypertrophy defined as a left ventricular mass index ≥ 96 g/m2 for women or ≥ 116 g/m2 for men. Severe aortic stenosis and arterial hypertension with mild left ventricular hypertrophy were exclusion criteria. All patients included were assessed for enzyme α-galactosidase A activity using dry spot testing. Genetic study was performed whenever the enzyme activity was decreased.Results:A total of 47 patients with a mean left ventricular mass index of 141.1 g/m2 (± 28.5; 99.2 to 228.5 g/m2] were included. Most of the patients were females (51.1%). Nine (19.1%) showed decreased α-galactosidase A activity, but only one positive genetic test − [GLA] c.785G>T; p.W262L (exon 5), a mutation not previously described in the literature. This clinical investigation was able to establish the association between the mutation and the clinical presentation.Conclusion:In a population of patients with left ventricular hypertrophy, we documented a Fabry disease prevalence of 2.1%. This novel case was defined in the sequence of a mutation of unknown meaning in the GLA gene with further pathogenicity study. Thus, this study permitted the definition of a novel causal mutation for Fabry disease - [GLA] c.785G>T; p.W262L (exon 5).

ResumoFundamento:A doença de Fabry é uma doença lisossomal de sobrecarga provocada pela deficiência da enzima α-galactosidase A como resultado de mutações no gene GLA. O envolvimento cardíaco carateriza-se por hipertrofia ventricular esquerda progressiva.Objetivo:Estimar a prevalência da doença de Fabry numa população com hipertrofia ventricular esquerda.Métodos:Os doentes foram avaliados para a presença de hipertrofia ventricular esquerda definida por massa do ventrículo esquerdo indexada como ≥ 96 g/m2 para mulheres ou ≥ 116 g/m2 para homens. Estenose aórtica severa e hipertensão arterial, com hipertrofia ventricular esquerda discreta, foram critério de exclusão. Todos os doentes incluídos foram avaliados para a atividade da enzima α-galactosidase A com testes de gota seca. No caso de atividade enzimática diminuída, realizava-se estudo genético.Resultados:Foram incluídos 47 doentes com uma média de massa indexada de 141,1 g/m2 (± 28,5; 99,2 a 228,5 g/m2]. A maioria (51,1%) dos doentes era do sexo feminino. Nove deles (19,1%) tinham diminuição da atividade da α-galactosidase A, mas apenas um teste genético foi positivo − [GLA] c.785G>T; p.W262L (éxon 5), uma mutação não descrita na literatura. O trabalho de investigação clínica permitiu estabelecer uma associação entre a mutação e a apresentação clínica.Conclusão:Em uma população de doentes com hipertrofia ventricular esquerda, documentamos uma prevalência de doença de Fabry de 2,1%. O novo caso foi definido na sequência de uma mutação de significado indeterminado no gene GLA com posterior estudo de patogenicidade. Este estudo permitiu, assim, definir uma nova mutação causal para doença de Fabry - [GLA] c.785G>T; p.W262L (éxon 5).