Mechanical Dispersion Assessed by Myocardial Strain in Patients After Myocardial Infarction for Risk Prediction of Ventricular Arrhythmia

ObjectivesThe aim of this study was to investigate whether myocardial strain echocardiography can predict ventricular arrhythmias in patients after myocardial infarction (MI).BackgroundLeft ventricular (LV) ejection fraction (EF) is insufficient for selecting patients for implantable cardioverter-defibrillator (ICD) therapy after MI. Electrical dispersion in infarcted myocardium facilitates malignant arrhythmia. Myocardial strain by echocardiography can quantify detailed regional and global myocardial function and timing. We hypothesized that electrical abnormalities in patients after MI will lead to LV mechanical dispersion, which can be measured as regional heterogeneity of contraction by myocardial strain.MethodsWe prospectively included 85 post-MI patients, 44 meeting primary and 41 meeting secondary ICD prevention criteria. After 2.3 years (range 0.6 to 5.5 years) of follow-up, 47 patients had no and 38 patients had 1 or more recorded arrhythmias requiring appropriate ICD therapy. Longitudinal strain was measured by speckle tracking echocardiography. The SD of time to maximum myocardial shortening in a 16-segment LV model was calculated as a parameter of mechanical dispersion. Global strain was calculated as average strain in a 16-segment LV model.ResultsThe EF did not differ between ICD patients with and without arrhythmias occurring during follow-up (34 ± 11% vs. 35 ± 9%, p = 0.70). Mechanical dispersion was greater in ICD patients with recorded ventricular arrhythmias compared with those without (85 ± 29 ms vs. 56 ± 13 ms, p < 0.001). By Cox regression, mechanical dispersion was a strong and independent predictor of arrhythmias requiring ICD therapy (hazard ratio: 1.25 per 10-ms increase, 95% confidence interval: 1.1 to 1.4, p < 0.001). In patients with an EF >35%, global strain showed better LV function in those without recorded arrhythmias (−14.0% ± 4.0% vs. −12.0 ± 3.0%, p = 0.05), whereas the EF did not differ (44 ± 8% vs. 41 ± 5%, p = 0.23).ConclusionsMechanical dispersion was more pronounced in post-MI patients with recurrent arrhythmias. Global strain was a marker of arrhythmias in post-MI patients with relatively preserved ventricular function. These novel parameters assessed by myocardial strain may add important information about susceptibility for ventricular arrhythmias after MI

Validation of self-reported and hospital-diagnosed atrial fibrillation: The HUNT study

Background: Self-reported atrial fibrillation (AF) and diagnoses from hospital registers are often used to identify persons with AF. The objective of this study was to validate self-reported AF and hospital discharge diagnoses of AF among participants in a population-based study. Materials and methods: Among 50,805 persons who participated in the third survey of the HUNT Study (HUNT3), 16,247 participants from three municipalities were included. Individuals who reported cardiovascular disease, renal disease, or hypertension in the main questionnaire received a cardiovascular-specific questionnaire. An affirmative answer to a question on physician-diagnosed AF in this second questionnaire defined self-reported AF diagnoses in the study. In addition, AF diagnoses were retrieved from hospital and primary care (PC) registers. All AF diagnoses were verified by review of hospital and PC medical records. Results: A total of 502 HUNT3 participants had a diagnosis of AF verified in hospital or PC records. Of these, 249 reported their AF diagnosis in the HUNT3 questionnaires and 370 had an AF diagnosis in hospital discharge registers before participation in HUNT3. The sensitivity of self-reported AF in HUNT3 was 49.6%, specificity 99.2%, positive predictive value (PPV) 66.2%, and negative predictive value (NPV) 98.4%. The sensitivity of a hospital discharge diagnosis of AF was 73.7%, specificity 99.7%, PPV 88.5%, and NPV 99.2%. Conclusion: Use of questionnaires alone to identify cases of AF has low sensitivity. Extraction of diagnoses from health care registers enhances the sensitivity substantially and should be applied when estimates of incidence and prevalence of AF are studied

Physical activity modifies the risk of atrial fibrillation in obese individuals: The HUNT3 study

Background Atrial fibrillation is the most common heart rhythm disorder, and high body mass index is a well-established risk factor for atrial fibrillation. The objective of this study was to examine the associations of physical activity and body mass index and risk of atrial fibrillation, and the modifying role of physical activity on the association between body mass index and atrial fibrillation. Design The design was a prospective cohort study. Methods This study followed 43,602 men and women from the HUNT3 study in 2006–2008 until first atrial fibrillation diagnosis or end of follow-up in 2015. Atrial fibrillation diagnoses were collected from hospital registers and validated by medical doctors. Cox proportional hazard regression analysis was performed to assess the association between physical activity, body mass index and atrial fibrillation. Results During a mean follow-up of 8.1 years (352,770 person-years), 1459 cases of atrial fibrillation were detected (4.1 events per 1000 person-years). Increasing levels of physical activity were associated with gradually lower risk of atrial fibrillation (p trend 0.069). Overweight and obesity were associated with an 18% (hazard ratio 1.18, 95% confidence interval 1.03–1.35) and 59% (hazard ratio 1.59, 95% confidence interval 1.37–1.84) increased risk of atrial fibrillation, respectively. High levels of physical activity attenuated some of the higher atrial fibrillation risk in obese individuals (hazard ratio 1.53, 95% confidence interval 1.03–2.28 in active and 1.96, 95% confidence interval 1.44–2.67 in inactive) compared to normal weight active individuals. Conclusion Overweight and obesity were associated with increased risk of atrial fibrillation. Physical activity offsets some, but not all, atrial fibrillation risk associated with obesity

The effect of intravenous adrenaline on electrocardiographic changes during resuscitation in patients with initial pulseless electrical activity in out of hospital cardiac arrest

Introduction Presence of electrocardiographic rhythm in the absence of palpable pulses defines pulseless electrical activity (PEA) and the electrocardiogram (ECG) may provide a source of information during resuscitation. The aim of this study was to examine the development of ECG characteristics during advanced life support (ALS) from Out-of-hospital cardiac arrest (OHCA) with initial PEA, and to explore the potential effects of adrenaline on these characteristics. Methods Patients with OHCA and initial PEA, part of randomized controlled trial of ALS with or without intravenous access and medications, were included. A total of 4840 combined observations of QRS complex rate (heart rate) and width were made by examining defibrillator recordings from 170 episodes of cardiac arrest. Results We found Increased heart rate (47 beats per minute) and reduced QRS complex width (62 ms) during ALS in patients who obtained return of spontaneous circulation (ROSC); while patients who received adrenaline but died increased their heart rate (22 beats per minute) without any concomitant decrease in QRS complex width. Conclusion ECG changes during ALS in cardiac arrest were associated with prognosis, and the administration of adrenaline impacted on these changes

Implantasjon av hjertestartere ved St. Olavs hospital 2006–15

BAKGRUNN Implantasjon av hjertestarter (implantable cardioverter defibrillator, ICD) er etablert behandling hos pasienter med høy risiko for plutselig hjertedød. Studiens formål var å kartlegge pasientkarakteristika, indikasjoner, hyppigheten av ICD-støt, komplikasjoner, reoperasjoner samt endringer over tid i ICD-behandlingen ved St. Olavs hospital. MATERIALE OG METODE Alle pasienter som fikk implantert hjertestarter ved St. Olavs hospital i perioden 2006–15 ble inkludert. Pasientene ble identifisert i pacemakerregisteret. Data ble hentet fra pacemakerregisteret og elektronisk pasientjournal. RESULTATER Studien inkluderte 598 pasienter (82 % menn, medianalder 65 år). Tidligere hjertestans eller alvorlig arytmi forelå hos 401 (67 %) av dem som fikk implantert hjertestarter. Koronarsykdom (n = 383) var vanligste underliggende årsak. I oppfølgingstiden (median 3,6 år) fikk 203 (34 %) av pasientene ICD-støt, 154 (26 %) fikk berettigede og 65 (11 %) fikk uberettigede støt. Hos 139 (23 %) pasienter oppstod komplikasjoner. 101 (17 %) pasienter døde i oppfølgingsperioden. FORTOLKNING Studien gir et godt grunnlag for kvalitetssikring av implantasjonsvirksomheten ved St. Olavs hospital. Kjønns- og aldersfordeling, indikasjon og underliggende årsaker for implantasjon samt hyppighet av støt og komplikasjoner samsvarer godt med tidligere publiserte data

Implantasjon av hjertestartere ved St. Olavs hospital 2006–15

BAKGRUNN Implantasjon av hjertestarter (implantable cardioverter defibrillator, ICD) er etablert behandling hos pasienter med høy risiko for plutselig hjertedød. Studiens formål var å kartlegge pasientkarakteristika, indikasjoner, hyppigheten av ICD-støt, komplikasjoner, reoperasjoner samt endringer over tid i ICD-behandlingen ved St. Olavs hospital. MATERIALE OG METODE Alle pasienter som fikk implantert hjertestarter ved St. Olavs hospital i perioden 2006–15 ble inkludert. Pasientene ble identifisert i pacemakerregisteret. Data ble hentet fra pacemakerregisteret og elektronisk pasientjournal. RESULTATER Studien inkluderte 598 pasienter (82 % menn, medianalder 65 år). Tidligere hjertestans eller alvorlig arytmi forelå hos 401 (67 %) av dem som fikk implantert hjertestarter. Koronarsykdom (n = 383) var vanligste underliggende årsak. I oppfølgingstiden (median 3,6 år) fikk 203 (34 %) av pasientene ICD-støt, 154 (26 %) fikk berettigede og 65 (11 %) fikk uberettigede støt. Hos 139 (23 %) pasienter oppstod komplikasjoner. 101 (17 %) pasienter døde i oppfølgingsperioden. FORTOLKNING Studien gir et godt grunnlag for kvalitetssikring av implantasjonsvirksomheten ved St. Olavs hospital. Kjønns- og aldersfordeling, indikasjon og underliggende årsaker for implantasjon samt hyppighet av støt og komplikasjoner samsvarer godt med tidligere publiserte data

Symptoms of anxiety and depression and risk of atrial fibrillation-the HUNT study

Background Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Anxiety and depression may activate the autonomic nervous system which is likely to play an important role in the etiology of AF. However, little is known about the association between symptoms of anxiety and depression and risk of AF. Objective This study aimed to assess the association between symptoms of anxiety and depression and risk of AF. Methods In a population-based study, 37,402 adult residents were followed for incident AF from 2006 to 2008 until 2015. Participants were classified according to data on anxiety and depression symptoms. Cox proportional regression models were used to adjust for common AF risk factors. Results During a median follow-up of 8.1 years, 1433 (3.8%) participants developed AF. In comparisons with no anxiety symptoms, the multivariable-adjusted hazard ratios (HRs) were 1.1 (95% CI: 0.9–1.5) for mild to moderate anxiety symptoms and 1.0 (95% CI: 0.8–1.4) for severe anxiety symptoms. In comparisons with no depression symptoms, the multivariable-adjusted HRs were 1.5 (95% CI: 1.2–1.8) for mild to moderate depression symptoms and 0.9 (95% CI: 0.6–1.3) for severe depression symptoms. Recurrent anxiety/depression symptoms were not associated with increased AF risk. Conclusions In this large, population-based study, we found no evidence of an association between symptoms of anxiety or severe depression and AF risk, even for recurrent anxiety or depression symptoms. An unexpected association of symptoms of mild to moderate depression with increased AF risk requires confirmation in other studies. Our findings add to the sparse literature on symptoms of anxiety and depression and risk of AF

Associations of asthma and asthma control with atrial fibrillation risk: Results from the Nord-Trøndelag health study (HUNT)

Importance Asthma, a chronic inflammatory airway disease, and atrial fibrillation (AF) share several common pathophysiological mechanisms. Research on the association between asthma and atrial fibrillation is lacking, and to our knowledge, no previous studies have assessed the dose-response association between levels of asthma control and AF. Objective To assess the association between asthma, levels of asthma control, and AF. Design, Setting, and Participants This prospective population cohort analyzed data on adults from a second and third iteration of the survey-based Nord-Trøndelag Health Study (HUNT) in Norway. All included participants were free from AF at baseline. Atrial fibrillation was ascertained by linking HUNT data with hospital records from the 2 hospitals in Nord-Trøndelag County. Data analysis was completed from May 2017 to November 2017. Exposures Self-reported asthma was categorized into 3 groups: those who had ever had asthma, those who self-report being diagnosed with asthma, and those who had active asthma. Asthma control was defined according to Global Initiative for Asthma guidelines and was categorized into controlled, partly controlled, and uncontrolled cases. Main Outcomes and Measures Atrial fibrillation. Results A total of 54 567 adults were included (of whom 28 821 [52.8%] were women). Of these, 5961 participants (10.9%) reported ever having asthma, 3934 participants (7.2%) reported being diagnosed with asthma, and 2485 participants (4.6%) reported having active asthma. During a mean (SD) follow-up of 15.4 (5.8) years, 2071 participants (3.8%) developed AF. Participants with physician-diagnosed asthma had an estimated 38% higher risk of developing AF (adjusted hazard ratio, 1.38 [95% CI, 1.18-1.61]) compared with participants without asthma. There was a dose-response association between levels of asthma control and risk of AF with the highest risk for AF in participants with uncontrolled asthma (adjusted hazard ratio, 1.74 [95% CI, 1.26–2.42]; P for trend < .001). Conclusions and Relevance Asthma and lack of asthma control were associated with moderately increased risks of AF in a dose-response manner. Further studies are needed to explore the underlying mechanisms and clarify causal pathways between asthma and AF

Prevalence, risk factors, and type of sleep apnea in patients with paroxysmal atrial fibrillation

Background Recent studies have suggested an association between sleep apnea (SA) and atrial fibrillation (AF). We aimed to study the prevalence, characteristics, risk factors and type of sleep apnea (SA) in ablation candidates with paroxysmal AF. Methods/Results We prospectively studied 579 patients with paroxysmal AF, including 157 women (27.1%) and 422 men (72.9%). Mean age was 59.9 ± 9.6 years and mean body mass index (BMI) 28.5 ± 4.5 kg/m2. SA was diagnosed using polygraphy for two nights at home. The Epworth Sleepiness Scale (ESS), STOP-Bang Questionnaire, and Berlin Questionnaire (BQ) assessed the degree of SA symptoms. A total of 479 (82.7%) patients had an apnea-hypopnea index (AHI) ≥ 5, whereas moderate-severe SA (AHI ≥ 15) was diagnosed in 244 patients (42.1%). The type of SA was predominantly obstructive, with a median AHI of 12.1 (6.7–20.6) (range 0.4–85.8). The median central apnea index was 0.3 (0.1–0.7). AHI increased with age, BMI, waist and neck circumference, body and visceral fat. Using the Atrial Fibrillation Severity Scale and the SF-36, patients with more severe SA had a higher AF burden, severity and symptom score and a lower Physical-Component Summary score. Age, male gender, BMI, duration of AF, and habitual snoring were independent risk factors in multivariate analysis (AHI ≥ 15). We found no association between ESS and AHI (R2 = 0.003, p = 0.367). Conclusions In our AF population, SA was highly prevalent and predominantly obstructive. The high prevalence of SA detected in this study may indicate that SA is under-recognized in patients with AF. None of the screening questionnaires predicted SA reliably