Effects of reperfusion on complete heart block complicating anterior myocardial infarction

Neue Aspekte der Schrittmacherindikation bei atrioventrikulären Überleitungsstörungen

Die neuen europäischen Leitlinien zur Herzschrittmachertherapie bilden den aktuellen Stand des Wissens ab. Im Vergleich zu den vorhergehenden Leitlinien ist die Klarstellung, dass die Empfehlungen auch für Vorhofflimmern/-flattern mit AV-Block und für intermittierende und permanente bzw. symptomatische und asymptomatische infranodale AV-Blockierungen gleichermaßen gelten, neu. Bei Synkopen im Kontext mit Schenkelblockierungen wird die Bedeutung der elektrophysiologischen Untersuchung und des prolongierten kontinuierlichen EKG-Monitorings unterstrichen, was auch für Leitungsstörungen nach Transkatheter-Aortenklappen-Implantation gilt. Bei AV-Block nach Myokardinfarkt und Herzoperation sollte 5 Tage auf ein Sistieren gewartet werden, wenn die Klinik des Patienten es erlaubt. Neuromuskuläre Erkrankungen erfordern aufgrund des erhöhten Risikos für eine rasche Progression eine Schrittmacherimplantation oft bereits bei leichteren Überleitungsstörungen.

An Interesting Case of Atherosclerotic Occlusion of the First Septal Perforator in a Physically Young and Fit Individual Causing Complete Heart Block

Complete heart block (CHB) is an unfortunate complication of an anterior and inferior myocardial infarction (MI). We present a case of an atherosclerotic occlusion of the first septal perforator leading to CHB requiring permanent pacemaker placement in a young patient. A 33-year-old healthy white male presented to the emergency department with an episode of syncope. His vitals were stable, and his physical exam was unremarkable. His electrocardiogram (EKG) showed CHB and ST elevations in V1, V2, and V3 suggestive of septal MI. He underwent emergent left heart catheterization which revealed significant stenosis of the proximal left anterior descending (LAD) artery, proximal diagonal artery, and the first septal perforator. An intervention was done with stent placement in the LAD and insertion of a temporary pacemaker. After removal of the temporary pacemaker two days later, the patient developed asystole with alternating bundle branch block which prompted immediate reinsertion of the temporary pacemaker which was replaced later with a permanent pacemaker. The patient was stable afterward and discharged.

The persistent atherosclerotic occlusion of the first septal perforator prevented adequate perfusion of the conduction system, even after revascularization of the proximal LAD. In conclusion, it is essential to acknowledge that difficulty to revascularize an occluded septal perforator raises the need for a permanent pacemaker to prevent a CHB.

Spontaneous recovery of complete atrioventricular block complicating acute anterior wall ST elevation myocardial infarction

BACKGROUND

Complete atrioventricular block complicating acute anterior wall ST elevation myocardial infarction (MI) is classically considered one of the worst prognostic indicators.

METHODS

We present the case of a gentleman who developed complete atrioventricular block during the course of acute anterior wall ST elevation MI, and had spontaneous resolution of the same. Mechanisms of spontaneous resolution of complete atrioventricular block in the setting of acute MI are discussed. Attention is drawn to a subgroup of patients, albeit a minority, who have a better prognosis owing to reversible causes than classically expected and seen.

RESULTS

Clinical features suggested that this patient had reocclusion of the infarct-related artery after thrombolysis on presentation and spontaneous reperfusion.

CONCLUSION

Coronary angiography provides invaluable information for decision making in such clinical scenarios. Complete atrioventricular block due to reversible ischaemia produced by reocclusion of an infarct-related artery should be reversible by percutaneous coronary angioplasty of the infarct-related artery. We suggest that reversible causes be considered before attributing atrioventricular block to irreversible damage, which would require a permanent pacemaker implantation. This would be more significant in most of the developing world, where resources are scarce.

Complete Atrioventricular Block Complicating Acute Anterior Myocardial Infarction can be Reversed with Acute Coronary Angioplasty

Introduction: A retrospective case series of acute anterior myocardial infarction (MI) patients complicated by complete atrioventricular block (AVB) treated with acute percutaneous transluminal coronary angioplasty (PTCA). Clinical Picture: Eight patients with anterior MI and complete AVB underwent acute PTCA between 2000 and 2005. Mean onset of complete AVB was 16.6 ± 16.9 hours from chest pain onset. Treatment: All patients underwent successful PTCA to the left anterior descending artery. Outcome: Complete AVB resolved with PTCA in 88%; mean time of resolution was 89 ± 144 minutes after revascularisation. One patient had permanent pacemaker implanted at Day 12 after developing an 8-second ventricular standstill during hospitalisation but not pacing-dependent on follow-up. The rhythm on discharge for the other surviving patients was normal sinus rhythm. Conclusion: This case series suggests that complete AVB complicating anterior MI is reversible with acute PTCA and survivors are not at increased risk of recurrent AVB. Nevertheless, this condition is associated with extensive myocardial damage and high mortality during the acute hospitalisation was not improved with correction of AVB with temporary pacing. Key words: Acute percutaneous transluminal coronary angioplasty

Prognostic significance of bundle-branch block in acute myocardial infarction: the importance of location and time of appearance

BACKGROUND

The presence of bundle-branch block (BBB) is associated with high mortality rates and is considered an important predictor of poor outcome in patients with acute myocardial infarction (AMI).

HYPOTHESIS

The objective of this study was to assess the prognostic significance of BBB in patients with AMI depending on its form of presentation.

METHODS

A multicenter prospective 1-year follow-up study involving 1,239 consecutive patients diagnosed with AMI was performed.

RESULTS

Bundle-branch block was present in 177 cases (14.2%), associated with worse clinical characteristics, lower rate of thrombolytic therapy, and higher mortality: in-hospital (23.8 vs. 9.7%, p < .01) and 1-year (40.9 vs. 16.9%, p < 0.01). Compared with right BBB (n = 135), left BBB (n = 42) was more often associated with female gender and higher prevalence of cardiovascular diseases, but had a similar 1-year mortality. In the absence of heart failure or complete atrioventricular (AV) block, there was no difference in in-hospital mortality of patients with BBB (n = 76) and without BBB (n = 786) (2.6 vs. 3.9%). Compared with existing BBB (n = 113), BBB of new appearance (n = 64) was more often accompanied by complete AV block and heart failure and higher in-hospital and 1-year mortality rates. Only BBB of new appearance was an independent predictor of mortality: in-hospital (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.1-4.7) and 1-year mortality (OR 3.2, 95% CI, 1.7-9.1).

CONCLUSIONS

In patients with AMI, the classification of BBB according not only to location but also to time of appearance is of practical interest. New BBB is an independent predictor of short- and long-term mortality.

Impact of PercuSurge GuardWire device on prevention and reduction of recovery time from complete heart block in patients with acute inferior myocardial infarction undergoing primary percutaneous coronary intervention

Second-degree heart block or complete heart block (CHB) is a relatively frequent complication of acute inferior wall myocardial infarction (AIWMI). This study investigated whether the PercuSurge device can prevent procedure-related CHB or can shorten CHB recovery time in patients with AIWMI undergoing primary percutaneous coronary intervention (PCI). Between May 2002 and April 2005, a PercuSurge device was utilized in 113 patients (study population, group 1) with AIWMI due to obstruction of the right coronary artery (RCA) with a reference lumen diameter (RLD) > or = 3.5 mm. The control subjects (group 2) consisted of 119 patients who experienced AIWMI due to RCA obstruction with a RLD > or = 3.5 mm from May 2000 to April 2002. The combined incidence of new onset of CHB following the interventional procedure was significantly higher in group 2 than in group 1. Additionally, recovery time from CHB to first-degree heart block or normal sinus rhythm was remarkably longer in group 2 than in group 1. Furthermore, the duration of hospitalization in group 2 was significantly longer than in group 1. Multiple stepwise analyses demonstrated that the PercuSurge device was the only independent predictor of preventing new onset of CHB during the procedure. Additionally, this mechanical device along with final TIMI-3 flow and final myocardial blush grade > or = 2 was independently associated with reducing recovery time from CHB. In conclusion, the PercuSurge device can prevent procedure-related CHB and shorten the recovery time for CHB in patients with AIWMI undergoing primary PCI.

Usefulness of either or both left and right bundle branch block at baseline or during follow-up for predicting death in patients following acute myocardial infarction

The presence or onset of bundle branch block (BBB) is associated with increased mortality in patients after acute myocardial infarction (AMI). The risk increases with age. We assessed the prognostic power of BBB patterns for predicting clinical outcomes in patients after high-risk AMI. In the OPTIMAAL trial, the effects of losartan versus captopril were compared in 5,477 patients with heart failure and/or evidence of left ventricular dysfunction after MI. The association between clinical outcomes and the presence of left or right BBB at randomization (median 3 days after AMI) or occurring during follow-up (mean 2.7 years) was assessed using Cox regression models. At randomization, 8% of patients (n = 438) showed BBB patterns; 3.7% (n = 203) showed left BBB and 4.3% (n = 235) showed right BBB patterns. In patients with left BBB, there was an increased risk of all-cause death and cardiovascular death. In patients with right BBB, there was increased risk of sudden cardiac death/resuscitated cardiac arrest. During follow-up, another 4.9% (n = 272) developed BBB patterns; 2.8% (n = 153) developed left BBB and 2.17% (n = 119) developed right BBB. Left BBB was associated with increased risk for all-cause death, cardiovascular death, and sudden cardiac death/resuscitated cardiac arrest, whereas right BBB was related to increased risk of sudden cardiac death/resuscitated cardiac arrest. In conclusion, our results confirm and quantify previous observations showing substantially increased mortality in patients with BBB patterns at baseline or occurring soon after AMI.

Complete atrioventricular block complicating acute myocardial infarction in the thrombolytic era. SPRINT Study Group and the Israeli Thrombolytic Survey Group. Secondary Prevention Reinfarction Israeli Nifedipine Trial

OBJECTIVES

We assessed the incidence, associated clinical parameters and prognostic significance of complete atrioventricular block (CAVB) complicating acute myocardial infarction (AMI) in the thrombolytic era and compared them to data from the prethrombolytic era.

BACKGROUND

The introduction of new therapeutic modalities to treat AMI, aimed to enhance coronary reperfusion and to limit myocardial necrosis, was expected to decrease the incidence of CAVB and to improve prognosis. However, there are only limited data regarding the incidence and the prognosis of AMI patients with CAVB in the thrombolytic era.

METHODS

Data from 3,300 patients from the Israeli Thrombolytic Surveys (prospective, nationwide surveys of consecutive patients with AMI in all 25 coronary-care units in Israel in 1992 and 1996) were analyzed and compared with data from 5,788 patients included in the SPRINT (Secondary Prevention Reinfarction Israeli Nifedipine Trial) Registry (1981 to 1983).

RESULTS

During the 1990s, the incidence of CAVB was 3.7% compared with 5.3% in the 1980s, p = 0.0007. In the 1990s, mortality of patients with CAVB was significantly higher than in those without CAVB at 7 days (odds ratio [OR] = 4.05 95% CI [confidence interval] 2.34 to 6.82, 30 days OR = 3.98 [95% CI 2.44 to 6.43] and one-year hazard ratio [HR] = 2.36, [95% CI 1.68 to 3.30]) and similar in thrombolysis-treated and not-treated patients. Mortality of patients with CAVB has not changed significantly between the two periods; seven-day OR = 0.82 (95% CI 0.46 to 1.43); 30-day OR = 0.78 (95% CI 0.45 to 1.33) and one-year HR = 0.79 (95% CI 0.54 to 1.56), respectively, in the 1990s as compared to a decade earlier.

CONCLUSIONS

The incidence of CAVB complicating AMI is lower in the thrombolytic era than in the prethrombolytic era. Mortality among patients with CAVB is still high and has not declined within the last decade. The AMI patients who develop CAVB in the thrombolytic era have significantly worse prognosis than do patients without CAVB.

Mechanisms and clinical significance of transient atrioventricular block during dobutamine stress echocardiography

OBJECTIVES

The purpose of this study was to investigate the possible mechanism and the clinical significance of transient atrioventricular block (AVB) during dobutamine stress echocardiography (DSE).

BACKGROUND

Transient AVB occurs rarely during DSE; however, the mechanisms responsible for blocks are unclear.

METHODS

A retrospective analysis of clinical, echocardiographic, catheterization, revascularization and head-up tilting test data was conducted in patients who developed transient AVB during DSE.

RESULTS

A total of 302 patients with known or suspected coronary artery disease (CAD) underwent DSE before coronary angiography between November 1997 and August 1998. Transient AVB developed in 12 patients during the test. Mobitz I block was noted in six patients and Mobitz II block in the other six patients. Nine of these 12 patients were subsequently shown to have CAD and three had no significant coronary artery stenosis. Mobitz II block was observed only in patients with CAD, while Mobitz I block occurred in three patients with and three patients without CAD (p < 0.05). Eight of the nine patients with CAD underwent a successful coronary angioplasty with or without stenting and a repeat DSE revealed no recurrence of heart block except in one patient. Head-up tilting test in the 12 patients revealed a positive response in three of the nine patients with and all three patients without CAD. A negative head-up tilting test was likely to be observed in patients with, as compared with those without, CAD in this study population (p < 0.05).

CONCLUSIONS

Transient AVB is not an infrequent manifestation during DSE. Both myocardial ischemia and neurally mediated vagal reflex may be responsible for this phenomenon. The development of Mobitz II block during DSE is indicative of the presence of CAD. A successful revascularization in patients with CAD who develop transient AVB may abolish this phenomenon.

Acute myocardial infarction and complete bundle branch block at hospital admission: clinical characteristics and outcome in the thrombolytic era. GUSTO-I Investigators. Global Utilization of Streptokinase and t-PA [tissue-type plasminogen activator] for Occluded Coronary Arteries

OBJECTIVES

We sought to assess the outcome of patients with acute myocardial infarction (MI) and bundle branch block in the thrombolytic era.

BACKGROUND

Studies of patients with acute MI and bundle branch block have reported high mortality rates and poor overall prognosis.

METHODS

The North American population with acute MI and bundle branch block enrolled in the Global Utilization of Streptokinase and t-PA [tissue-type plasminogen activator] for Occluded Coronary Arteries (GUSTO-I) trial was matched by age and Killip class with an equal number of GUSTO-I patients without conduction defects.

RESULTS

Of all 26,003 North American patients in GUSTO-I, 420 (1.6%) had left (n = 131) or right (n = 289) bundle branch block. These patients had higher 30-day mortality rates than matched control subjects (18% vs. 11%, p = 0.003, odds ratio [OR] 1.8) and were more likely to experience cardiogenic shock (19% vs. 11%, p = 0.008, OR 1.78) or atrioventricular block/asystole (30% vs. 19%, p < 0.012, OR 1.57) and to require ventricular pacing (18% vs. 11%, p = 0.006, OR 1.73). Bundle branch block also carried an independent 53% higher risk for 30-day mortality. Thirty-day mortality rates for patients with complete, partial and no reversion of the bundle branch block were 8%, 12% and 20%, respectively (two-tailed chi-square test for trend 5.61, p = 0.02, OR 0.34 for complete reversion, OR 0.55 for partial reversion).

CONCLUSIONS

Bundle branch block at hospital admission in patients with acute MI predicts in-hospital complications and poor short-term survival.

Recurrent syncope due to complete atrioventricular block, a rare presenting symptom of otherwise silent coronary artery disease: successful treatment by PTCA

A patient presented with recurrent syncope and episodes of AV block preceded by asymptomatic ST segment elevation on ambulatory monitoring. Coronary angiography revealed a severe stenosis in the midsegment of the right coronary artery (RCA). Successful PTCA and stent insertion abolished further episodes of syncope.