Uffe Jakob Ortved Gang

High-degree atrioventricular block complicating ST-segment elevation myocardial infarction in the era of primary percutaneous coronary intervention

AIMS Primary percutaneous coronary intervention (pPCI) has replaced thrombolysis as treatment-of-choice for ST-segment elevation myocardial infarction (STEMI). However, the incidence and prognostic significance of high-degree atrioventricular block (HAVB) in STEMI patients in the pPCI era has been only sparsely investigated. The objective of this study was to assess the incidence, predictors and prognostic significance of HAVB in STEMI patients treated with pPCI. METHODS AND RESULTS This study included 2073 STEMI patients treated with pPCI. The patients were identified through a hospital register and the Danish National Patient Register. Both registers were also used to establish the diagnosis of HAVB. All-cause mortality was the primary endpoint. During a median follow-up of 2.9 years [interquartile range (IQR) 1.8-4.0] 266 patients died. High-degree atrioventricular block was documented in 67 (3.2%) patients of whom 25 died. Significant independent predictors of HAVB included right coronary artery occlusion, age >65 years, female gender, hypertension, and diabetes. The adjusted mortality rate was significantly increased in patients with HAVB compared to patients without HAVB [hazard ratio = 3.14 (95% confidence interval 2.04-4.84), P< 0.001]. A landmark-analysis 30 days post-STEMI showed equal mortality rates in the two groups. CONCLUSION The incidence of HAVB in STEMI patients treated with pPCI has been reduced compared with reports from the thrombolytic era. However, despite this improvement high-degree AV block remains a severe prognostic marker in the pPCI era. The mortality rate was only increased within the first 30 days. High-degree atrioventricular block patients who survived beyond this time-point thus had a prognosis equal to patients without HAVB.

Diastolic dysfunction predicts new-onset atrial fibrillation and cardiovascular events in patients with acute myocardial infarction and depressed left ventricular systolic function: a CARISMA substudy

AIMS The aim of this study was to investigate the association between diastolic dysfunction and long-term occurrence of new-onset atrial fibrillation (AF) and cardiac events in patients with acute myocardial infarction (AMI) and left ventricular (LV) systolic dysfunction. METHODS AND RESULTS The study was performed as a substudy on the CARISMA study population. The CARISMA study enrolled 312 patients with an AMI and LV ejection fraction <or=40%. Patients were implanted with an implantable loop recorder and followed for 2 years. Sixty-two patients had a full echocardiographic assessment of the diastolic function using tissue Doppler analysis performed 6 weeks after the AMI. The endpoints were: (i) new-onset AF and (ii) major cardiovascular events (MACE) defined as re-infarction, stroke, or cardiovascular death. Twenty-four patients had diastolic dysfunction, whereas 38 patients had normal diastolic function. Diastolic dysfunction was associated with an increased risk of new-onset AF [HR = 5.30 (1.68-16.75), P = 0.005] and MACE [HR = 4.70 (1.25-17.75), P = 0.022] after adjustment for age, sex, NYHA class, and hypertension. CONCLUSION Diastolic dysfunction in post-MI patients with LV systolic dysfunction predisposes to new-onset AF and MACE.

Heart rhythm at the time of death documented by an implantable loop recorder

AIMS The aims of this study were to describe arrhythmias documented with an implantable loop recorder (ILR) in post-acute myocardial infarction (AMI) patients with left ventricular dysfunction at the time of death and to establish the correlation to mode of death. METHODS AND RESULTS Post-mortem ILR device interrogations were analysed from patients dying in the CARISMA study. Mode of death was classified by a modified CAST classification. Twenty-six patients died with an implanted ILR. Of these, 16 had an electrocardiogram recorded at the time of death. Ventricular tachycardia (VT)/ventricular fibrillation (VF) was terminal rhythm in eight patients and bradyarrhythmias were observed in another eight patients. Of the deaths with peri-mortem recordings, seven were classified as sudden cardiac death (SCD). In six of these, VF was documented at the time of death. Six monitored deaths were classified as non-SCD (NSCD) of which only two had recordings of VT/VF, whereas four had bradyarrhythmias. All peri-mortem recordings in non-cardiac death (NCD) were bradyarrhythmia. CONCLUSION Long-term monitoring in a population of post-AMI patients with left ventricular ejection fraction < or =40% showed that VT/VF and bradyarrhythmia each accounted for half of the recorded events at the time of death. The ILR confirmed that ventricular tachyarrhythmias are associated primarily with SCD, whereas bradyarrhythmias and electromechanical dissociation seems dominant in NSCD and NCD. The study was registered at ClinicalTrials.gov: NCT00145119.

Autonomic Dysfunction and New‐Onset Atrial Fibrillation in Patients With Left Ventricular Systolic Dysfunction After Acute Myocardial Infarction: A CARISMA Substudy

Predicting New‐Onset AF. Background: Atrial fibrillation (AF) increases morbidity and mortality in patients with previous myocardial infarction and left ventricular systolic dysfunction. The purpose of this study was to identify patients with a high risk for new‐onset AF in this population using invasive and noninvasive electrophysiological tests.

New-onset atrial fibrillation predicts malignant arrhythmias in post–myocardial infarction patients—A Cardiac Arrhythmias and RIsk Stratification after acute Myocardial infarction (CARISMA) substudy

BACKGROUND After myocardial infarction (MI) the risk of sudden cardiac death due to arrhythmias is substantial. OBJECTIVE The purpose of this study was to investigate if new-onset atrial fibrillation (AF) is associated with development of potential malignant brady- and tachyarrhythmias after an acute MI. METHODS The study included 277 post-MI patients from the CARISMA study with left ventricular ejection fraction ≤ 40%, New York Heart Association class I, II, or III and no history of AF. All patients were implanted with an implantable cardiac monitor within 4 to 27 days after an acute MI and followed every 3 months for 2 years. Time-dependent association between new-onset AF > 30 s and the development of bradyarrhythmias and/or ventricular tachyarrhythmias were investigated using Cox proportional hazard regressions. RESULTS New-onset AF was associated with an increased risk of bradyarrhythmias when adjusting for male gender and baseline age, left ventricular ejection fraction and QRS width (HR = 2.8 [1.3-5.8], P = .006). Similarly, new-onset AF predicted ventricular tachyarrhythmias when adjusting for New York Heart Association class ≥ II and baseline QRS width (HR = 2.3 [1.2-4.4], P = .019). After dividing ventricular tachyarrhythmias into subgroups of non-sustained ventricular tachycardia (VT), sustained VT and ventricular fibrillation (VF), new-onset AF was significantly associated with an increased risk of non-sustained- and sustained VT but not VF (non-sustained VT: HR = 3.5 [1.7-7.2], P < .001, sustained VT: HR = 4.2 [1.1-15.7], P = .035, VF: HR = 1.1 [0.2-5.8], P = .877). CONCLUSION In patients surviving a MI with reduced left ventricular systolic function, new-onset AF is associated with a significantly increased risk of developing ventricular brady- and tachyarrhythmias.

Risk markers of late high-degree atrioventricular block in patients with left ventricular dysfunction after an acute myocardial infarction: a CARISMA substudy

AIMS High-degree atrioventricular block (HAVB) after acute myocardial infarction (AMI) is associated with increased risk of mortality. Risk markers and predictors of HAVB occurring after AMI are largely unknown. The aim of this study was to assess the predictive value of risk markers derived from a series of non-invasive and invasive tests for the development of HAVB documented by an implantable loop recorder (ILR) in late convalescent phases of an AMI. METHODS AND RESULTS The study included 292 patients with AMI and subsequent left ventricular dysfunction without prior HAVB or implanted pacemaker. An ILR was implanted for continuous arrhythmia surveillance. Risk stratification testing was performed at inclusion and 6 weeks after AMI. The tests included echocardiography, electrocardiogram (ECG), 24 h Holter monitoring, and an invasive electrophysiological study. High-degree atrioventricular block was documented in 28 (10%) patients during a median follow-up of 2.0 (0.4-2.0) years. Heart rate variability (HRV) measures and non-sustained ventricular tachycardia occurring at the week 6 Holter monitoring were highly predictive of HAVB. Power law slope <-1.5 ms(2)/Hz was the most powerful HRV parameter (HR = 6.02 [2.08-17.41], P < 0.001). CONCLUSION Late HAVB development in post-AMI patients with left ventricular dysfunction can be predicted by risk stratification tests. Measures of HRV reflecting autonomic dysfunction revealed the highest predictive capabilities.

Clinical significance of late high-degree atrioventricular block in patients with left ventricular dysfunction after an acute myocardial infarction--a Cardiac Arrhythmias and Risk Stratification After Acute Myocardial Infarction (CARISMA) substudy.

BACKGROUND High-degree atrioventricular block (HAVB) is a frequent complication in the acute stages of a myocardial infarction associated with an increased rate of mortality. However, the incidence and clinical significance of HAVB in late convalescent phases of an AMI is largely unknown. The aim of this study was to assess the incidence and prognostic value of late HAVB documented by continuous electrocardiogram (ECG) monitoring in post-AMI patients with reduced left ventricular function. METHODS The study included 286 patients from the CARISMA study with AMI and left ventricular ejection fraction of 40% or less. An insertable loop recorder was implanted 5 to 21 days after AMI for incessant arrhythmia surveillance. Furthermore, ECG documentation was supplemented by a 24-hour Holter monitoring conducted at week 6 post-AMI. The clinical significance of HAVB occurring more than 21 days after AMI was examined with respect to development of major heart failure events and major ventricular tachyarrhythmic events. RESULTS During a median follow-up of 1.9 years (interquartile range 0.9-2.0), late HAVB was documented in 30 patients. The risk of major heart failure events (hazard ratio [HR] 4.08 [1.38-12.09], P = .01) and major ventricular tachyarrhythmic events (HR = 5.41 [1.88-15.58], P = .002) were significantly increased in patients who developed late HAVB. CONCLUSION High-degree atrioventricular block documented by continuous ECG monitoring occurring more than 3 weeks after AMI is a frequent complication in post-AMI patients with left ventricular dysfunction. Furthermore, HAVB is associated with ominous prognostic implications of both potentially lethal arrhythmias and heart failure.

The predictive value of CHADS2 risk score in post myocardial infarction arrhythmias — A Cardiac Arrhythmias and RIsk Stratification after Myocardial infArction (CARISMA) substudy

BACKGROUND Previous studies have shown substantially increased risk of cardiac arrhythmias and sudden cardiac death in post-myocardial infarction (MI) patients. However it remains difficult to identify the patients who are at highest risk of arrhythmias in the post-MI setting. The purpose of this study was to investigate if CHADS₂ score (congestive heart failure, hypertension, age ≥75 years, diabetes and previous stroke/TCI [doubled]) can be used as a risk tool for predicting cardiac arrhythmias after MI. METHODS The study included 297 post-MI patients from the CARISMA study with left ventricular ejection fraction (LVEF) ≤40%. All patients were implanted with an implantable cardiac monitor (ICM) within 5 to 21 days post-MI and followed every three months for two years. Atrial fibrillation, bradyarrhythmias and ventricular tachycardias were diagnosed using the ICM, pacemaker or ICD. Patients were stratified according to CHADS₂ score at enrollment. Congestive heart failure was defined as LVEF ≤40% and NYHA class II, III or IV. RESULTS We found significantly increased risk of an arrhythmic event with increasing CHADS₂ score (CHADS₂ score=1-2: HR=2.1 [1.1-3.9], p=0.021, CHADS₂ score ≥ 3: HR=3.7 [1.9-7.1], p<0.001). This pattern was identical when dividing the arrhythmias into subgroups of atrial fibrillation, ventricular tachycardias and bradyarrhythmias. CHADS₂ score was similarly associated with the development of major cardiovascular events defined as reinfarction, stroke, and hospitalization for heart failure or cardiovascular death. CONCLUSION In the post-MI setting, CHADS₂ score efficiently identifies populations at high risk for cardiac arrhythmias.

Massive Electrical Storm at Disease Onset in a Patient with Brugada Syndrome

Patient: Male, 49 Final Diagnosis: — Symptoms: — Medication: — Clinical Procedure: — Specialty: — Objective: Rare disease Background: Brugada syndrome (BrS) is a genetic arrhythmogenic disease characterized by ST-segment elevations in the right precordial leads of the electrocardiogram (ECG). These ECG changes may be concealed and BrS may present with electrical storm characterized by recurrent ventricular tachycardia and fibrillation. Case Report: A 49-year-old previously healthy man was admitted with electrical storm. The patient received direct current (DC) cardioversion shocks and only after intravenous lidocaine did the electrical storm slowly subside with a total of 255 DC shocks administered during the first 24 h after admission. He fully recovered and received an implantable cardioverter-defibrillator. Subsequent drug challenge with flecainide revealed type 1 BrS. Conclusions: Massive electrical storm can be the first symptom of BrS and the diagnostic ECG changes may be concealed at presentation. Although hundreds of DC shocks may be required during initial treatment, full recovery can be achieved.

Response to Letter Regarding Article, “Long-Term Recording of Cardiac Arrhythmias With an Implantable Cardiac Monitor in Patients With Reduced Ejection Fraction After Acute Myocardial Infarction: The Cardiac Arrhythmias and Risk Stratification After Acute Myocardial Infarction (CARISMA) Study”

We appreciate the very relevant comments by Ravensbergen and colleagues, and agree that the Cardiac Arrhythmias and Risk Stratification After Acute Myocardial Infarction (CARISMA) Study1 had several limitations. As we also pointed out, the main limitation, regarding the definition and diagnosis of tachyarrhythmias, was that the rate had to be ≥125 beats per minute for every beat of at least 16 consecutive beats. Thus, tachyarrhythmias of 16 consecutive beats, and with varying R-R intervals longer than 480 ms, could not be recorded by the implantable …