Compromised atrial coronary anatomy is associated with atrial arrhythmias and atrioventricular block complicating acute myocardial infarction

Prognostic Significance of Newly Diagnosed Atrial Fibrillation After Acute Myocardial Infarction: A Study of 184,980 Medicare Patients

We aimed to determine whether newly diagnosed atrial fibrillation (AF) predicted cardiovascular events and death after myocardial infarction (AMI) in a large nationwide cohort of patients. All Medicare beneficiaries aged >65 years who were discharged alive after a diagnosis of AMI between January 1, 2007 and December 31, 2008 were identified. Main exposure was a diagnosis of AF during admission or within 90 days after discharge. Primary outcome was a composite of recurrent AMI, stroke and all-cause mortality. Secondary outcomes were each of recurrent AMI, stroke and all-cause mortality. We used Cox proportional hazards regression to assess the relationship between AF and time-to-event outcomes with follow up ending at 3 years. Of 184,980 patients, 9.1 % had AF; 40.6 % were male; 82.8 % were non-Hispanic whites. Mean age was 79.1 ± 8.1 years. Overall, 15.7 % had subsequent AMI, 5.7 % had stroke and 43.9 % died during a mean follow up of 26.4 months. AF was associated with a significantly increased risk of the primary outcome (Hazard ratio (HR) = 1.10; 95 % confidence interval (CI): 1.07-1.12). AF was also separately associated with significantly increased risk of recurrent AMI (HR = 1.09; 95 % CI: 1.04-1.14), stroke (HR = 1.29; 95 % CI: 1.21-1.37), and death (HR = 1.09; 95 % CI: 1.06-1.12). Neither age, race nor sex modified the effects of AF on primary or secondary outcomes. In conclusion, AF is a significant predictor of adverse cardiovascular outcomes and mortality after AMI. Further studies are needed to understand mechanisms by which AF alters outcomes in survivors of AMI.

Association of soluble suppression of tumorigenicity 2 with new-onset atrial fibrillation in acute myocardial infarction

Background The combination of acute myocardial infarction (AMI) and atrial fibrillation (AF) is still a thorny problem in the clinic. At present, there are few reports on the role of soluble suppression of tumorigenicity 2 (sST2) in AF after AMI. This study was to explore the predictive value of sST2 in patients with AMI for new-onset AF. Methods This is a single-center retrospective clinical observation study. We continuously included AMI patients from September 2019 to November 2021. The concentration of sST2 in blood samples was determined. During admission, suspicious heart rhythm was recorded by electrocardiogram (ECG) monitoring, and new-onset AF was confirmed by immediate body surface ECG. Results After multiple factors were included, age, right coronary artery (RCA), high sensitivity c-reactive protein (hs-CRP), left ventricular ejection fraction (LVEF), and sST2 were still risk factors for new-onset AF. The area under curve (AUC) value of age and sST2 was more than 0.7, which showed good diagnostic value. For re-evaluation, the sST2 was added to the clinical new-onset AF prediction model. It was found that the integrated discrimination improvement (IDI) and net reclassification index (NRI) in the model were improved significantly. Conclusion sST2 is an independent predictor of new-onset AF in patients with AMI and can improve the accuracy of the AF risk model.

Acute atrial ischemia associates with early but not late new-onset atrial fibrillation in STEMI patients treated with primary PCI: relationship with in-hospital outcomes

BACKGROUND

New-onset atrial fibrillation (NOAF), both early (EAF) or late (LAF), may complicate ST-segment elevation myocardial infarction (STEMI). The mechanisms underlying EAF or LAF are poorly described. We investigated atrial branch occlusion and EAF or LAF onset in STEMI patients undergoing primary percutaneous coronary intervention.

METHODS

This was a retrospective cohort study including 155 STEMI patients. Patients were divided into 3 groups: sinus rhythm (SR), EAF, or LAF. Clinical characteristics, angiographic features including occlusion of atrial branches, namely ramus ostia cavae superioris (ROCS), atrio-ventricular node artery (AVNA), right intermediate atrial artery (RIAA), and left intermediate atrial artery, were assessed. We also investigated in-hospital adverse events (AEs) and death.

RESULTS

Mean age was 63.8±11.9 years; 78.7% were men. NOAF was detected in 22 (14.2%) patients: 10 (6.4%) EAF and 12 LAF (7.7%). Compared to EAF, LAF patients were older (p=0.013), with higher GRACE risk score (p=0.014) and Killip class (p=0.015), depressed ejection fraction (p=0.007), elevated filling pressures (p=0.029), higher C-reactive protein (p=0.014) and more with thrombolysis in myocardial infarction flow <3 (p=0.015). Compared to SR, EAF was associated with higher prevalence of occluded ROCS (p=0.010), AVNA (p=0.005), and RIAA (p<0.001). Moreover, EAF patients had more frequently ≥2 diseased atrial branches than SR (19.5%, p<0.001) and LAF (25%, p<0.030) patients. LAF patients had a higher in-hospital AEs (p=0.019 vs SR; p=0.029 vs EAF) and death (p=0.004 vs SR).

CONCLUSIONS

The occlusion of atrial branches is associated with EAF but not LAF following STEMI. LAF patients had worse in-hospital AEs and mortality.

Impact of Atrial Fibrillation on Acute Coronary Syndrome-Analysis of In-Hospital Outcomes and 30-Day Readmissions

With an aging population and significant overlap of risk factors, the cohort of patients with acute coronary syndrome (ACS) and concomitant atrial fibrillation (AF) is a sizable and growing one, with implications on cardiac reserve, anticoagulation and antiplatelet therapies, and related complications. The present study uses a large national database to analyze the impact of AF on patients admitted with an ACS. We queried the 2012 to 2014 National Readmissions Database to identify patients admitted with an ACS using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9 CM) codes. These patients were then subcategorized based on the presence or absence of AF. Analysis of their initial hospitalization, 30-day readmissions and healthcare utilization and the economic burden was performed. Among 1,558,205 patients with ACS, 270,966 (17.4%) were noted to have concomitant AF. At baseline, these patients were older and more likely female, with a significantly higher burden of comorbidities. Patients with AF had longer and more complicated index hospitalizations with significantly higher mortality rates (8.6% vs 4.6%). Coronary artery bypass graft was the preferred method of revascularization in patients with AF as compared to percutaneous coronary intervention. The 30-day readmissions were higher in the AF group (15.6 vs 10.8%), largely driven by noncardiac causes. This was associated with higher healthcare utilization with longer hospitalizations during index admission. Patients admitted with ACS and concomitant AF is a high-risk population with increased in-hospital complications and mortality, as well as short term readmissions. Coronary artery bypass graft appears favored over percutaneous coronary intervention for revascularization in patients with AF.

Arrhythmia in Acute Myocardial Infarction: A Six-Month Retrospective Analysis From the National Institute of Cardiovascular Diseases

Introduction Acute myocardial infarction (AMI) is a devastating medical emergency that requires immediate pharmacological and radiological intervention. With the advent of techniques such as percutaneous coronary intervention (PCI), pacemakers, and percussion pacing, survival rates have improved significantly. However, there are certain factors and complications associated with AMI that still lead to a high mortality rate, such as old age, advanced heart disease, diabetes mellitus (DM), and arrhythmias. Factors such as the type of arrhythmia, the heart rate, and the level at which dissociation occurs between atrial and ventricular rhythm all influence mortality and morbidity rates. Outcomes are further influenced by the sex of the patient, the type of AMI [ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (NSTEMI)], history of smoking, arrival times at the hospital, presence of hyperglycemia, previous history of cardiac surgery, and the need for a temporary pacemaker or a permanent pacemaker. As with most scientific studies, local data from Pakistan is hard to find on this topic as well. With this study, we hope to contribute valuable information and updates to the study of a developing problem from the developing world. Objective We aimed to analyze the frequency and outcomes of different types of arrhythmia in AMI. Methods This study involved a retrospective observational cohort. It was conducted at the National Institute of Cardiovascular Diseases (NICVD), Karachi from January 2019 to July 2019 (six months). All data were retrieved from the online database at the NICVD. Written consent was obtained from all patients. Patient confidentiality was ensured at all times. Results A total of 500 patients were included in the study. The mean age of our cohort was 56.17 ±14.01 years. NSTEMI was more prevalent than STEMI. Sinus arrhythmia (SA) was the most frequently recorded arrhythmia and had the best survival rates. Atrioventricular (AV) nodal blocks and ventricular tachycardia (VT) had the worst outcomes. The overall mortality rate was 11.4%, and the mean in-hospital length of stay was 2.07 ±1.54 days. Smoking increased mortality in all cases. Conclusions AMI is complicated by several types of arrhythmia. SA is the most common arrhythmia in AMI. Mortality in AMI is largely due to AV nodal blocks and VT. Smoking increases mortality in all cases.

New-Onset Atrial Fibrillation in St-Segment Elevation Myocardial Infarction: Predictors and Impact on Therapy And Mortality

Backgrund

New-onset atrial fibrillation complicating acute myocardial infarction represents an important challenge, with prognostic significance.

Objective

To study the incidence, impact on therapy and mortality, and to identify predictors of development of new-onset atrial fibrillation during hospital stay for ST-segment elevation myocardial infarction.

Methods

We studied all patients with ST-elevation myocardial infarction included consecutively, between 2010 and 2017, in a Portuguese national registry and compared two groups: 1 - no atrial fibrillation and 2 - new-onset atrial fibrillation. We adjusted a logistic regression model data analysis to assess the impact of new-onset atrial fibrillation on in-hospital mortality and to identify independent predictors of its development. A p value < 0.05 was considered significant.

Results

We studied 6325 patients, and new-onset atrial fibrillation was found in 365 (5.8%). Reperfusion was successfully accomplished in both groups with no difference regarding type of reperfusion. In group 2, therapy with beta-blockers and angiotensin-conversion enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) was less frequent, 20.6% received anticoagulation at discharge and 16.1% were on triple therapy. New-onset atrial fibrillation was associated with more in-hospital complications and mortality. However, it was not found as an independent predictor of in-hospital mortality. We identified age, prior stroke, inferior myocardial infarction and complete atrioventricular block as independent predictors of new-onset atrial fibrillation.

Conclusion

New-onset atrial fibrillation remains a frequent complication of myocardial infarction and is associated with higher rate of complications and in-hospital mortality. Age, prior stroke, inferior myocardial infarction and complete atrioventricular block were independent predictors of new onset atrial fibrillation. Only 36.7% of the patients received anticoagulation at discharge.

Procedural-related coronary atrial branch occlusion during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction and atrial arrhythmias at follow-up

OBJECTIVES

To evaluate the frequency of procedural-related atrial branch occlusion in ST-segment elevation myocardial infarction (STEMI) patients and its association with atrial arrhythmias at 1-year follow-up.

BACKGROUND

Atrial ischemia due to procedural-related coronary atrial branch occlusion in elective percutaneous coronary intervention (PCI) has been associated with atrial arrhythmias. Its role in a STEMI scenario is unknown.

METHODS

STEMI patients treated with primary PCI were classified according to the loss or patency of an atrial branch at the end of the procedure. The occurrence of atrial arrhythmias was documented on 24-hr Holter-ECG at 3 and 6 months or on ECG during 1-year follow-up visits.

RESULTS

Of 900 patients, 355 (age 61 ± 12 years, 79% male) underwent primary PCI involving the origin of an atrial branch. Procedural-related coronary atrial branch occlusion was observed in 18 (5%) individuals). During 1-year follow-up, 33% of patients with procedural-related atrial branch occlusion presented atrial arrhythmias, as compared with 55% in those with a patent atrial branch (p = .088). Age, no previous history of myocardial infarction, and a reduced flow in the culprit vessel were the only independent correlates of atrial arrhythmias.

CONCLUSIONS

The frequency of procedural-related atrial branch occlusion during primary PCI is low (5%) and is not associated with increased frequency of atrial arrhythmias at 1-year follow-up.

Cardiac computed tomography in patients with symptomatic new-onset atrial fibrillation, rule-out acute coronary syndrome, but with intermediate pretest probability for coronary artery disease admitted to a chest pain unit

Background

Atrial fibrillation (AF) and coronary artery disease (CAD) may be encountered coincidently in a large portion of patients. However, data on coronary artery calcium burden in such patients are lacking. Thus, we sought to determine the value of cardiac computed tomography (CCT) in patients presenting with new-onset AF associated with an intermediate pretest probability for CAD admitted to a chest pain unit (CPU).

Methods

Calcium scores (CS) of 73 new-onset, symptomatic AF subjects without typical clinical, electrocardiographic, or laboratory signs of acute coronary syndrome (ACS) admitted to our CPU were analyzed. In addition, results from computed tomography angiography (CTA) were related to coronary angiography findings whenever available.

Results

Calcium scores of zero were found in 25%. Median Agatston score was 77 (interquartile range: 1–270) with gender- and territory-specific dispersal. CS scores above average were present in about 50%, high (> 400)-to-very high (> 1000) CS scores were found in 22%. Overall percentile ranking showed a relative accordance to the reference percentile distribution. Additional CTA was performed in 47%, revealing stenoses in 12%. Coronary angiography was performed in 22% and resulted in coronary intervention or surgical revascularization in 7%. On univariate analysis, CS > 50th percentile failed to serve as an independent determinant of significant stenosis during catheterization.

Conclusions

Within a CPU setting, relevant CAD was excluded or confirmed in almost 50%, the latter with a high proportion of coronary angiographies and subsequent coronary interventions, underlining the diagnostic value of CCT in symptomatic, non-ACS, new-onset AF patients when admitted to a CPU.

The atherosclerosis of the sinus node artery is associated with an increased history of supra-ventricular arrhythmias: a retrospective study on 541 standard coronary angiograms

Background. The ischemic damage of the sinus node (SN) is a well known cause of cardiac arrhythmias and can be a consequence of any flow abnormality in the sinus node artery (SNA). Accordingly we aimed this retrospective study to: (1) evaluate the suitability of the standard coronary angiography to study the SNA and (2) determine if the percentage of subjects with a positive retrospective history of supra-ventricular arrhythmias (SVA) differs in patients with normal and diseased SNA ascertained at the time of coronary angiography.

Methods and Results. Out of the 541 coronary angiograms reviewed the SNA was visible for its entire course in 486 cases (89.8%). It was found to arise from the right side of the coronary circulation in 266 cases (54.7%) slightly more often than from the left, 219 cases (45.1%). One patient had 2 distinct SNA arising from either side of the coronary circulation. For the second objective, we studied the 333 patients with: (a) coronary artery disease (CAD), (b) properly evaluable SNA and (c) complete clinical history available. In 51 (15.3%) a SNA disease was found, 41.2% of them had a positive SVA history, mainly atrial fibrillation (AF), whereas only 7.4% of patients with a positive history of SVA could be found in the non-SNA diseased. This difference was statistically significant (P < 0.001).

Conclusions. (1) The evaluation of the SNA is feasible in clinical practice during a standard coronary angiography; (2) this may be relevant since angiographically detectable SNA disease was significantly associated with a positive history of SVA.

Microvasculature and incident atrioventricular conduction abnormalities in the Multi-Ethnic Study of Atherosclerosis (MESA)

Abnormalities of the microvasculature are linked to major cardiac events, but their role in the development of atrioventricular conduction abnormalities (AVCA) is unknown. We examined the association between central retinal arteriolar equivalent (CRAE), a measure of the microvasculature, and incident AVCA. This analysis included 3975 participants free of AVCA at baseline from the Multi-Ethnic Study of Atherosclerosis (MESA). Incident AVCA was defined as a composite of new heart rate-adjusted PR interval ⩾ 200 ms (first-degree AV block) and advanced block (second-degree or complete AV block) detected from the MESA exam 5 electrocardiogram (ECG). CRAE was measured from retinal photographs at exam 2. Both ECGs and retinal photographs were collected using standardized methods and read and graded at central core labs. Incident AVCA were present in 7.4% ( n=290) of the participants, of which 94% were first-degree AV block. Incident AVCA were increasingly more common in participants with narrower CRAE (4.6% in Q4, 6.4% in Q3, 7.0% in Q2 and 10.8% in Q1, p-value for trend < 0.0001). The socio-demographic and cardiovascular disease risk-adjusted odds of incident AVCA in the Q1 group (the group with the narrowest retinal arteriolar diameter) was nearly twice the odds in the Q4 group (OR: 1.68, 95% CI: 1.15–2.51). This association remained significant after adjustment for major ECG abnormalities and incident cardiovascular disease (Q1 vs Q4, OR: 1.65, 95% CI: 1.01–2.71). In conclusion, narrower retinal arteriolar caliber is associated with development of new AV conduction abnormalities.

Effect of cardiac rehabilitation on left atrial functions in patients with acute myocardial infarction

BACKGROUND

The objective of this study was to analyze the effects of cardiac rehabilitation (CR) on the atrial function of patients with acute myocardial infarction (AMI) who had been successfully revascularized through percutaneous coronary intervention (PCI).

METHODS

Forty-two AMI patients having undergone CR were enrolled in this observational study. Assessments were performed before and after 6 weeks of CR. Left atrial strain analysis was carried out by two-dimensional speckle tracking echocardiography. Left ventricular ejection fraction (LVEF) was measured by the biplane Simpson's method. Pulsed-wave Doppler at the tip of mitral valve leaflets enabled us to measure early (E) and late (A) diastolic filling velocities, deceleration time (DT) of early filling velocity and isovolumic relaxation time (IVRT). Left ventricle tissue velocity was measured by tissue Doppler imaging of the lateral mitral annulus (e') and E/e' was subsequently calculated. Ratio of E/e' to left atrium (LA) peak strain was used to estimate LA stiffness.

RESULTS

Following CR, LVEF (P=0.010), LA strain (P<0.001) and LA stiffness (P=0.013) all showed improvement, while other parameters remained unchanged.

CONCLUSION

Post-AMI cardiac rehabilitation and revascularization by PCI might have favourable effects on LA function.

New-onset atrial fibrillation is associated with cardiovascular events leading to death in a first time myocardial infarction population of 89,703 patients with long-term follow-up: a nationwide study

Background

New‐onset atrial fibrillation (AF) is reported to increase the risk of death in myocardial infarction (MI) patients. However, previous studies have reported conflicting results and no data exist to explain the underlying cause of higher death rates in these patients.

Methods and Results

All patients with first acute MI between 1997 and 2009 in Denmark, without prior AF, were identified from Danish nationwide administrative registers. The impact of new‐onset AF on all‐cause mortality, cardiovascular death, fatal/nonfatal stroke, fatal/nonfatal re‐infarction and noncardiovascular death, were analyzed by multiple time‐dependent Cox models and additionally in propensity score matched analysis. In 89 703 patients with an average follow‐up of 5.0±3.5 years event rates were higher in patients developing AF (n=10 708) versus those staying in sinus‐rhythm (n=78 992): all‐cause mortality 173.9 versus 69.4 per 1000 person‐years, cardiovascular death 137.2 versus 50.0 per 1000 person‐years, fatal/nonfatal stroke 19.6/19.9 versus 6.2/5.6 per 1000 person‐years, fatal/nonfatal re‐infarction 29.0/60.7 versus 14.2/37.9 per 1000 person‐years. In time‐dependent multiple Cox analyses, new‐onset AF remained predictive of increased all‐cause mortality (HR: 1.9 [95% CI: 1.8 to 2.0]), cardiovascular death (HR: 2.1 [2.0 to 2.2]), fatal/nonfatal stroke (HR: 2.3 [2.1 to 2.6]/HR: 2.5 [2.2 to 2.7]), fatal/nonfatal re‐infarction (HR: 1.7 [1.6 to 1.8]/HR: 1.8 [1.7 to 1.9]), and non‐ cardiovascular death (HR: 1.4 [1.3 to 1.5]) all P<0.001). Propensity‐score matched analyses yielded nearly identical results (all P<0.001).

Conclusions

New‐onset AF after first‐time MI is associated with increased mortality, which is largely explained by more cardiovascular deaths. Focus on the prognostic impact of post‐infarct AF is warranted.

Structural and Functional Remodeling of the Left Atrium: Clinical and Therapeutic Implications for Atrial Fibrillation

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice. Despite advances in our understanding of the pathophysiology of this complex arrhythmia, current therapeutic options remain suboptimal. This review aimed to delineate the atrial structural and functional remodeling leading to the perpetuation of AF. We explored the complex changes seen in the atria in various substrates for AF and the therapeutic options available to prevent these changes or for reverse remodeling. Here we also highlighted the emerging role of aggressive risk factor management aimed at the arrhythmogenic atrial substrate to prevent or retard AF progression.

Atrial fibrillation in acute ST-elevation myocardial infarction: clinical and prognostic features

Atrial fibrillation (AF) is a common arrhythmia in the setting of acute coronary syndrome and acute ST-elevation myocardial infarction (STEMI). This review summarizes recent evidence on the clinical and prognostic significance of pre-existent and new-onset AF in acute STEMI patients and highlights new emerging predictors of AF development in the era of contemporary treatment.

Reversibility of atrioventricular block according to coronary artery disease: results of a retrospective study

Background and Objectives

The causal relationship of clinically-significant atrioventricular block (AVB) and coronary artery disease (CAD) is uncertain. We investigated whether CAD is related to irreversible AVB that requires treatment with a permanent pacemaker.

Subjects and Methods

We included 188 consecutive patients with new-onset AVB considering pacemaker, who had undergone invasive or noninvasive coronary evaluation. Patients were divided into one of 2 groups: irreversible AVB who underwent implantation of permanent pacemaker {irreversible block (IB) group, n=173} or reversible AVB {reversible block (RB) group, n=15}.

Results

In IB group, significant CAD was observed in 44 patients (25.4%) and there were 2 (1.2%) patients with acute myocardial infarction (AMI). In RB group, 14 patients (93.3%) had CAD (p<0.001) and 13 patients (86.7%) presented with AMI (p<0.001). On the aspect of CAD type and reversibility of AVB, 13/15 (86.7%) patients of AMI, 0/2 (0%) of unstable angina, and 1/41 (2.4%) of stable angina had reversible AVB.

Conclusion

AVB in patients with AMI is usually reversible. Therefore, permanent pacemaker implantation should be delayed in cases of AMI. AVB in patients with CAD other than AMI is usually irreversible.

Atrial Fibrillation in Acute Coronary Syndrome

Atrial fibrillation (AF) is a common cardiac arrhythmia occurring in an estimated 2.7 to 6.1 million people in the United States. The risk factors for the development of AF are very similar to those for developing coronary artery disease, and AF is often associated with acute coronary syndrome (ACS) and acute myocardial infarction (MI). Overall, AF complicates approximately 10% of acute infarcts and the incidence rate is comparable between the thrombolytic and percutaneous coronary intervention (PCI) eras. Prior to widespread use of thrombolysis, the incidence of AF during acute MI was as high as 18%. Moreover, AF is a marker for increased long term mortality post infarct. Over the past 20 years, the relative mortality risk for patients with AF post MI has remained around 2.5 times that for patients without AF. The treatment of AF in the setting of MI and ACS is similar to without; however there is often an increased urgency to limiting rapid heart rates which may exacerbate acute ischemia. Cardioversion and IV amiodarone may be utilized more liberally in this setting than otherwise. Anticoagulation is usually required both for the treatment of MI and possible PCI, as well as for cerebral vascular accident prevention from AF-induced thromboembolism. Often patients require triple-therapy for optimal treatment of both conditions, and special considerations for bleeding risk must be analyzed.

Coronary artery disease affecting the atrial branches is an independent determinant of atrial fibrillation after myocardial infarction

BACKGROUND

During acute myocardial infarction (MI), the incidence of atrial fibrillation (AF) is 6% to 22%, and its occurrence in this setting is associated with increased short- and long-term morbidity and mortality.

OBJECTIVE

The purpose of this case control study was evaluate the characteristics associated with the development of new-onset AF.

METHODS

Of 2,460 consecutive patients with acute MI, 149 (6%) were identified as having AF within 7 days of MI. After excluding patients with prior AF, previously documented heart failure, reduced left ventricular (LV) ejection fraction, valvular heart disease, LV hypertrophy, AF after coronary artery bypass grafting, or pericarditis; we identified 42 AF patients in whom coronary anatomy was assessed by invasive angiography and cardiac structure and function was evaluated using transthoracic echocardiography. Another 42 patients from the same cohort with MI but no AF matched for age, gender, and LV ejection fraction were studied as controls.

RESULTS

AF patients were more likely to present with an inferior MI (P = .002) but less likely to present with ST-segment elevation MI (P = .02). Univariate associations with AF included indexed left atrial volume (P <.001), LV filling pressure (E/e'; P = .001), right atrial branch disease (P <.001), left atrial branch disease (P = .009), sinoatrial branch disease (P <.001), left main stem disease (P = .02), and time from onset of symptoms to coronary intervention (P = .002). In multivariable analysis, right and left coronary artery atrial branch disease (P = .02) were predictors of AF post-MI.

CONCLUSION

Coronary artery disease affecting the atrial branches is an independent predictor for the development of AF after MI.

Capillary supply to the sinus node in subjects with long-term atrial fibrillation

BACKGROUND

Atrial ischemia, and sinus node ischemia in particular, may be involved in the pathogenesis of atrial fibrillation. In this study we compared the sinus node blood capillary content in normal hearts in sinus rhythm and in pathologic hearts with chronic atrial fibrillation and we analyzed the ultrastructural features of such capillaries.

METHODS

Sinus node biopsy specimens were obtained from 16 patients in chronic atrial fibrillation undergoing open heart surgery. Control sinus node specimens of normal hearts were obtained at autopsy from 7 subjects. Specimens were processed for immunohistochemical, light microscopy and transmission electron microscopy analysis and compared grossly and with morphometric techniques.

RESULTS

The proportion of sinus node tissue corresponding to capillaries, defined as blood vessel density (or BVD), was estimated as 1.06 +/- 1.47% for the atrial fibrillation group versus 2.12 +/- 2.0% for controls (p < 0001). Internal capillary diameter averaged 21.6 microm in the atrial fibrillation group and 24.2 microm in controls (p = 0.175), whereas external diameter averaged 32.2 microm in the atrial fibrillation group and 38.9 microm in controls (p = 0.052). Ultrastructural analysis demonstrated scarce and interrupted myoendocardial bridges and abnormal deposits of elastic fibers under the endothelial basal membrane at the level of precapillary sphincters and metaarterioles of atrial fibrillation specimens.

CONCLUSIONS

There is a significant reduction in the amount of capillaries in the sinus node of hearts in chronic atrial fibrillation. Our findings would support a potential association between sinus node tissue ischemia and chronic atrial fibrillation.

Left atrial infarction: a case report and review of the literature

The majority of cardiac related deaths are due to ischemic heart disease, with the most common clinical scenario being severe coronary artery atherosclerosis resulting in left ventricular myocardial infarction. However, infarction of other cardiac chambers does occur, and often has specific clinical associations. We report a case of a 70-year-old man who suffered from left atrial infarction that resulted in a transmural rupture of his left atrium. The patient had a history of rheumatic heart disease, mitral valve stenosis, and severe atherosclerotic coronary artery disease. Four days before death, he underwent mitral valve replacement and left circumflex coronary artery bypass. Two days later, he developed atrial fibrillation. On the day of death, he had decreased mental status, questionable seizure activity, hematemesis, ventricular tachycardia, and eventually asystole. At autopsy, he had significant hemopericardium with a fibrinous pericarditis and bilateral hemothoraces (total blood volume: 1250 mL). A 0.1 to 0.2 cm left atrial transmural defect was identified. The prosthetic mitral valve was free of vegetations, and completely intact. Similarly, the left circumflex artery bypass graft was completely patent and unremarkable. Severe calcific atherosclerosis was of his native left circumflex and left main coronary arteries. Microscopic examination revealed acute myocardial infarction of the left atrium at the rupture site. The anatomy of atrial circulation as well as the pathology and consequences of atrial infarction are discussed.

Post PCI atrial fibrillation

Atrial fibrillation (AF) is a major arrhythmia with a high prevalence among population. AF is not uncommon in the setting of coronary artery disease, including myocardial infarction (MI) and acute coronary syndromes (ACS). Percutaneous coronary interventions (PCI) have significantly improved outcomes of patients with acute MI and acute coronary syndromes. Nevertheless, the AF was reported to occur in patients with MI and ACS undergoing PCI. New onset AF after PCI for MI and ACS, though being infrequent, was associated with worse clinical course and prognosis. The predictive value of AF has tendency to change in parallel with improvements of reperfusion strategies and comprehensive treatment. Observational studies suggest better patency of culprit vessels achieved by PCI was accompanied by improvement in signal-averaged electrocardiography indices of atrial electrophysiological properties and higher rate of restoration of sinus rhythm during primary PCI as compared with thrombolysis. The adequate management of arrhythmia is required to reduce the risk of complications.