Left and right ventricular function in inferior acute myocardial infarction and significance of advanced atrioventricular block

Of 139 consecutive patients with a first inferior acute myocardial infarction, 26 (19%) had advanced atrioventricular (AV) block and 113 (81%) did not. All were evaluated by 2-dimensional echocardiography (2-D echo) and radionuclide angiography. Patients with advanced AV block had lower radionuclide left ventricular (LV) ejection fraction (51 +/- 10 vs 58 +/- 11%, p less than 0.01), higher LV wall motion score on 2-D echo (5.6 +/- 2.6 vs 3.1 +/- 2.7, p less than 0.001), lower radionuclide right ventricular (RV) ejection fraction (32 +/- 15 vs 39 +/- 16%, p less than 0.001) and higher RV wall motion score on 2-D echo (3.4 +/- 1.7 vs 1.5 +/- 2, p less than 0.002) than did patients without AV block. The incidence rate of RV dysfunction was higher in patients with advanced AV block (78 vs 40%, p less than 0.02), and the mortality rate was also higher (although not significantly) in patients with advanced AV block (15 vs 6%). In conclusion, patients with inferior acute myocardial infarction and advanced AV block have larger infarct sizes (as seen on radionuclide angiography and 2-D echo) and lower RV and LV function than patients without AV block. This finding may explain the higher mortality rate observed in this group.     

Complete atrioventricular block complicating inferior wall acute myocardial infarction treated with reperfusion therapy. TAMI Study Group

Previous studies report larger myocardial infarcts and increased in-hospital mortality rates in patients with inferior wall acute myocardial infarction (AMI) and complete atrioventricular block (AV), but the clinical implications of these complications in patients treated with reperfusion therapy have not been addressed. The clinical course of 373 patients--50 (13%) of whom developed complete AV block--admitted with inferior wall AMI and given thrombolytic therapy within 6 hours of symptom onset was studied. Acute patency rates of the infarct artery after thrombolytic therapy were similar in patients with or without AV block. Ventricular function measured at baseline and before discharge in patients with complete AV block showed a decrement in median ejection fraction (-3.5 vs -0.4%, p = 0.03) and in median regional wall motion (-0.14 vs +0.24 standard deviations/chord, p = 0.05). The reocclusion rate was higher in patients with complete AV block (29 vs 16%, p = 0.03). Patients with complete AV block had more episodes of ventricular fibrillation or tachycardia (36 vs 14%, p less than 0.001), sustained hypotension (36 vs 10%, p less than 0.001), pulmonary edema (12 vs 4%, p = 0.02) and a higher in-hospital mortality rate (20 vs 4%, p less than 0.001), although the mortality rate after hospital discharge was identical (2%) in the 2 groups. Multivariable logistic regression analysis revealed that complete AV block was a strong independent predictor of in-hospital mortality (p = 0.0006). Thus, despite initial successful reperfusion, patients with inferior wall AMI and complete AV block have higher rates of in-hospital complications and mortality.     

Predictors and importance of congestive heart failure in patients with acute inferior myocardial infarction

Inferior myocardial infarction (MI) is considered to have a more favorable prognosis than anterior wall MI but includes high risk groups with increased mortality and morbidity. It is well known that congestive heart failure (CHF) complicating acute MI has poor prognosis. In this study we assessed the clinical and prognostic significance of CHF and the predictive value of the baseline demographic and clinical variables for CHF in patients with acute inferior MI. A total of 350 patients with acute inferior MI were included. In group A there were 26 patients (7.4%) with CHF, and in group B there were 324 patients (92.6%) without this complication. Baseline clinical and demographic characteristics and in-hospital complications of the groups were assessed. In group A patients were older (67.6±9.5 vs 53.7±10.9 years, p<0.0001) and there were more female patients (50% vs 15%, p<0.00001) compared to group B. The prevalence of diabetes mellitus (58% vs 16%) and precordial ST segment depression on admission ECG (81% vs 50%) were significantly higher in group A compared to group B (p<0.00001 and p=0.002 consecutively). In group A there was a higher rate of righ ventricular (25% vs 23%), posterior (26% vs 24%) and posterolateral myocardial infarction (19% vs 14%), but the differences were not statistically different. In group A patients had significantly higher rate of second- or third-degree AV block (46% vs 8%, p<0.00001), cardiogenic shock (35% vs 1%, p<0.00001) and mortality (46% vs 3%, p<0.00001) compared to group B. In a multivariate regression analysis diabetes mellitus (p=0.0003) and precordial ST segment depression on admission ECG (p=0.002) were found as the independent predictors of in-hospital CHF in patients with acute inferior MI. CHF and ST segment depression on admission ECG were found as the independent predictors of in-hospital mortality (p<0.00001, p=0.04 consecutively). Patients with CHF complicating acute inferior MI have more unfavorable demographic and clinical characteristics on admission, higher rate of in-hospital complications and mortality. History of diabetes mellitus and precordial ST segment depression on admission ECG have an independent predictive value for CHF in this particular group of patients.     

Factors associated with late onset of advanced atrioventricular block in acute Q wave inferior infarction

To elucidate the clinical characteristics associated with advanced atrioventricular (AV) block that appears relatively late (more than 24 hours) after the onset of myocardial infarction (MI), 101 patients with acute Q wave inferior MI were studied. Fourteen patients had late-onset advanced AV block, and 87 patients were free of AV block. The hospital mortality rate was 11%. Multivariate analysis was performed to determine the important variables associated with the occurrence of late advanced AV block and hospital mortality rates based on 12 clinical variables. Colloid osmotic pressure, right atrial pressure, serum potassium level, and number of segments with advanced asynergy were the significant factors associated with the occurrence of late advanced AV block, whereas advanced asynergic segments and alveolar arterial oxygen difference were important in the consideration of hospital mortality rates. Therefore not only the extent of myocardial ischemia but also the increases in the extracellular potassium level and interstitial fluid are some of the factors that are associated with the occurrence of late advanced AV block in acute inferior MI. Late advanced AV block, in itself, has no significant influence on hospital mortality rates.     

心电图J／R比值对下壁心肌梗死并发房室阻滞的预测价值

目的探讨急性下壁心肌梗死早期心电图表现对高度房室阻滞的预测价值以及与冠状动脉病变的关系。方法分析97例急性下壁心肌梗死患者早期心电图（下壁导联）J／R≥0．5的发生情况，部分病例结合冠脉造影结果，探讨其对房室阻滞的预测价值。结果27例（21．6％）在心肌梗死急性期发生二度以上房室阻滞。有房室阻滞者，心电图下壁导联J／R≥0．5多于无房室阻滞者（69．56％vs30．44％，p〈0．01）。冠状动脉造影显示，有房室阻滞者，右冠状动脉近中段的高度狭窄明显多于无房室阻滞者（100％vs58．33％）。结论急性下壁心肌梗死伴房室阻滞者的病损冠脉以右冠状动脉多见，下壁导联心电图J／R≥0．5对下壁心肌梗死合并房室阻滞的发生有一定的预测价值。     

Effect of aminophylline in patients with atropine-resistant late advanced atrioventricular block during acute inferior myocardial infarction

Background: Advanced atrioventricular (AV) block is a frequent complication in patients with acute inferior myocardial infarction (AIMI). This conduction abnormality is associated with narrow QRS complex in conducted or junctional escape beats, suggesting that the site of block is the AV node; however, its pathophysiology has not been properly established. Hypothesis: This study investigated the effect of aminophylline in eight patients (5 men, 3 women, age range 51 to 78 years, mean 67.5 ± 8.8 years) with atropine-resistant late advanced AV block during AIMI. Methods: Advanced AV block was late in appearance in all patients, starting 2 to 5 days after AIMI, and consisted of second-degree Mobitz II type in two patients and of complete AV block in six patients; all patients had narrow QRS complexes. Before aminophylline administration, all patients had a temporary pacemaker installed which was switched off throughout the study. They were given intravenous atropine (1 mg) that was found to be ineffective. One-half h after atropine, the first aminophylline injection (240 mg) was given intravenously over 10 min. One h following the first injection, a second aminophylline dose (240 mg) was administered. Electrocardiographic rhythm strips were obtained before and after drug administration, and the type of AV block and atrial and ventricular rate were noted. Results: Aminophylline restored 1:1 conduction with first-degree AV block in six patients, Mobitz I AV block in one patient, and normal sinus rhythm in one patient. Mean atrial and ventricular rates before aminophylline were 104 ± 16 beats/min and 57 ± 9 beats/min. respectively, and after drug administration 95 ± 25 beats/min and 89 ± 17 beats/min, respectively, (p = 0.012). Conclusion: These results indicate that aminophylline improves AV conduction in atropine-resistant late advanced AV block complicating AIMI.     

Long-term prognostic significance of atrioventricular block in inferior acute myocardial infarction

Among 477 consecutive patients admitted for inferior acute myocardial infarction (AMI), 2nd or 3rd degree atrioventricular (AV) block developed in 88 (20%). Compared with the 359 without AV block, these 88 patients presented a higher incidence of Killip class greater than 1 (52% vs 28%, P less than 0.001), pericarditis (30% vs 17%, P less than 0.01), atrial fibrillation (26% vs 11%, P less than 0.01), complete bundle branch block (12% vs 4%, P less than 0.01) and in-hospital mortality (24% vs 4%, P less than 0.001). The 3-year post-hospital mortality was not significantly different in the two groups (12% vs 15%). Among the 88 patients with AV block, those who died at hospital were older (66 +/- 11 vs 59 +/- 11 years, P less than 0.05), had a higher incidence of Killip class greater than 1 (86% vs 42%, P less than 0.001) and bundle branch block (29% vs 7%, P less than 0.05). Thus, patients with inferior AMI who developed AV block had a poor hospital outcome but long-term prognosis was similar in hospital survivors who had AV block and in those without this complication.     

Clinical setting and prognostic significance of high degree atrioventricular block in acute inferior myocardial infarction: a study of 144 patients

High degree AV block occurred in 144 of 843 patients consecutively admitted because of acute inferior myocardial infarction and was associated with more extensive myocardial damage and a higher mortality rate, as compared to those without AV block.Patients with power failure at the time of appearance of high degree AV block and a ventricular rate of less than 50 per minute, seemed to profit from pacemaker therapy.By contrast in patients with power failure and a ventricular rate of more than 50 per minute, pacemaker insertion did not affect immediate prognosis.     

急性心肌梗死伴发房室传导阻滞的临床分析

目的　探讨急性心肌梗死病人不同时期发生房室传导阻滞的临床特点及预后。方法　采用非创伤性心电监测及心电图检查 ,对 3 8例AMI发生AVB病例 ,根据心电图分期 ,分为超急性期、演变期和恢复期三组 ,对AVB发生的时间、持续时间、程度 ,临床特点及预后进行分析。结果　 87 5 %房室传导阻滞在急性心梗起病后 1 2小时内出现。超急性期发生AVB较演变期、恢复期发生AVB的时间早 ,持续时间短、程度重 ,严重并发症发生率高。阿托品类药或异丙肾上腺素治疗的病人多数有不同程度的改善 ,预后良好。结论　急性心肌梗死病人超急性期发生AVB较演变期和恢复期发生AVB的病情重 ,并发症多而严重 ,用阿托品类药或异丙肾上腺素治疗的病人 ,多数有不同程度的改善。大多数AMI合并AVB不用起搏器治疗。     

Predictors of Early and Late Atrioventricular Block Requiring Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: A Single-Center Experience

PurposeComplete heart block requiring permanent pacemaker can occur early following transcatheter aortic valve replacement (TAVR) due to mechanical compression of the aortic valve annulus and associated atrio-ventricular (AV) conduction system. Data are limited regarding late PM implantation after TAVR. The purpose of this study was to determine predictors of early vs. late PM implantation post-TAVR procedure.MethodsBaseline characteristics of patients who required PM <7 days following TAVR were compared with patients who required a PM >7 days to 1 year following TAVR using Chi-Square and multivariate regression analysis.ResultsThere were 362 TAVR patients, of which 39 (10.4%) received a PM after TAVR. Of these 18 (4.6%) patients required PM within 7 days after TAVR, and 21 (5.8%) required PM after 7 days and up to 1 year later. Right bundle branch block (RBBB) (OR 6.721, CI 2.3–36.9, p < 0.005) was a positive predictor of early PM placement. Left bundle branch block (LBBB) (OR = 3.5, CI 1.19–10.80, p-value < 0.05) and atrial fibrillation (AF) (OR = 3.5, 1.36–9.4 p < 0.05) were predictors for late PM. Early and late PM were associated with a longer median hospital stay compared to no PM (4.9 ± 4.86 days vs. 10.1 ± 10.04 days vs. 6.10 ± 6.02 days). The incidence of heart failure was higher in the late PM group. The overall motility was not increased in early and late PM compared to no PM.ConclusionPatients requiring PM implant after TAVR was 10.4%, of which 5.8% need PM >7 days post-TAVR. RBBB is a predictor for early PM. AF and LBBB were predictors for late PM.     

Prognostic significance of the implantation of a temporary pacemaker in patients with acute myocardial infarction

OBJECTIVE: Indication of temporary pacemakers in patients during acute myocardial infarction was widely studied in the pre-thrombolytic era without having determined whether the generalization of fibrinolysis might have changed the overall incidence and significance of temporary pacemakers. Our aim was to determine the incidence and the prognostic significance of insertion of temporary pacemakers in patients with acute myocardial infarction. PATIENTS AND METHODS: In a study involving 1,239 patients consecutively admitted to hospital with acute myocardial infarction we studied clinical characteristics and prognosis depending on temporary pacemaker insertion or not. We performed an univariate analysis on in-hospital mortality and those selected variables were introduced in to a logistic regression analysis. RESULTS: A temporary pacemaker was indicated in 55 patients (4.4%), prophylactically in 22% and therapeutically in 78%. Temporary pacemakers were inserted in 55% of the patients with advanced AV block and in the 10% of the patients with bundle-branch block. Pacemaker insertion was associated with higher number of affected leads in the ECG, and higher CK peak, regardless of the association with thrombolysis. The following complications were more often observed in patients with temporary pacemakers: atrial fibrillation, heart failure, right bundle-branch block, advanced atrioventricular block and in-hospital mortality (45.4 vs 10.2%; p < 0.001). Need for a temporary pacemaker was less frequent in patients treated with thrombolytics compared with those not treated (3.0 vs 6.1%; p < 0.02). Pacemaker insertion had an independent value for predicting in-hospital mortality (OR = 5.51; 95% CI, 2.71-11.19). CONCLUSION: The insertion of a temporary pacemaker in acute myocardial infarction is less frequent nowadays than on the pre-thrombolytic era. Pacemaker insertion is associated with higher indices of infarct extension and in-hospital mortality, having independent prognostic value on the in-hospital mortality.     

Skin aging parameters: A window to heart block

Background

Skin acts as a mirror to the internal state of the body.

Hypothesis

We tried to find the relation between skin aging parameters and the incidence of degenerative AV block.

Methods

This study included 97 patients divided into 2 groups; group D comprised 49 patients with advanced‐degree AV block, and group C comprised the 48 matched control group. All were subjected to full history taking, thorough clinical examination, calculation of intrinsic skin aging score, and resting 12‐lead surface electrocardiography (ECG). ECG for all patients assessed left ventricular end‐systolic diameter, left ventricular end‐diastolic diameter, ejection fraction, left atrium (LA) diameter, aortic root diameter, mitral annular calcification, aortic sclerosis. Coronary angiography was also performed when indicated for patients in group D.

Results

Patients in group D had a higher percentages of uneven pigmentation, fine skin wrinkles, lax appearance, seborrheic keratosis, total score > 7 (38 [77.55%] vs 10 [20.83%]), mitral annular calcification score of 33 (67.34%) vs 5 (10.41%), aortic sclerosis score of 21 (42.85%) vs 4 (8.33%), and mean LA diameter of 39.98 ± 5.52 vs 36.21 ± 3 mm (P < 0.001). Total score > 6 is the best cutoff value to predict advanced‐degree heart block with 89.79% sensitivity and 64.58% specificity. Seborrheic keratosis was the strongest independent predictor.

Conclusions

Any population with a total intrinsic skin aging score of >6 is at high risk for developing advanced‐degree AV block and should undergo periodic ECG follow‐up for early detection of any conduction disturbance in the early asymptomatic stages to minimize sudden cardiac death.     

Acute myocardial infarction due to the left main coronary artery occlusion: Electrocardiographic patterns,angiographic findings,revascularization and in-hospital outcomes

BackgroundPrimary angioplasty improves outcomes of acute myocardial infarction (AMI). However, in the highest risk subgroups, the mortality remains high despite modern catheter-based reperfusion therapy. This study analyzed patients with AMI caused by the left main coronary artery unstable lesion, a subgroup considered to be associated with very high early mortality.MethodsA multicenter registry enrolled 6742 consecutive patients with AMI. Ninety-seven patients (1,4% of the entire study population) had left main as the infarct related artery. Baseline clinical characteristics, ECG patterns, coronary angiographic and echocardiographic data were correlated with the revascularization therapies used and with in-hospital outcomes.ResultsTwenty-five patients (25,8%) died during the hospital stay. The deceased patients were older, had more freqently bundle branch block on the admission ECG, had higher Killip class on presentation, more frequently had TIMI flow <3 and PCI success rate was 72% (vs. 100% among survivors). Left main coronary artery (LMCA) lesion impaired distal flow (TIMI flow 0–2 on presentation) in 35 patients: the most frequent ECG presentation pattern for these LMCA occlusions was ST segment elevation (n=17), followed by RBBB (n=9; with LAH 6 and without LAH 3), LBBB (n=6) and ST segment depression (n=3). In other words: acute LMCA occlusion presents in 51% with ECG changes other than ST segment elevations. Patients with TIMI flow 0–2 had higher Killip class on admission, lower ejection fraction and higher in-hospital mortality (37% vs. 20%), when compared to those with TIMI flow 3 on the initial angiogram.ConclusionsDespite modern interventional therapy, acute myocardial infarction caused by the left main coronary artery obstruction bears high early mortality. The presence of bundle branch block, diminished TIMI flow on the initial angiogram, higher age and Killip class are related with increased mortality.     

Serial plasma catecholamine response early in the course of clinical acute myocardial infarction: Relationship to infarct extent and mortality

Clinical and experimental evidence suggest that sympathoadrenal activation contributes to mortality in patients with ischemic heart disease. To determine the level of sympathoadrenal activation in the very early phase of acute myocardial infarction (AMI) and to determine if location of infarction (anterior versus inferior) was related to sympathoadrenal activation, we studied norepinephrine (NE) and epinephrine (E) within 4 hours after the onset of symptoms and prior to any rise in plasma creatine kinase (CK). Mean (± SE) initial (NE = 591 ± 111 pg/ml and E = 73 ± 19 pg/ml), peak (NE = 1356 ± 178 and E ± 1098 ± 608) and average (NE = 815 ± 142 and E = 252 ± 68) plasma catecholamine concentrations were considerbly above normal (NE = 228 ± 10 and E = 34 ± 2 pg/ml, n 60) and values were similar for inferior and anterior infarctions. During an 18-month follow-up, three patients died in whom the AMI mean NE and E and peak CK were higher than in the eight late survivors. Thus the three AMI patients with peak EP values > 1000 died, whereas the eight AMI patients with peak EP values < 1000 survived (p < 0.01). The magnitude of sympathoadrenal activation early in the course of clinical AMI appeared related to the extent of myocardial damage and late mortality.     

Changes in left ventricular function after intracoronary streptokinase infusion in clinically evolving myocardial infarction

Left ventricular (LV) contrast cineventriculograms were obtained in 174 patients with evolving acute myocardial infarction (AMI) treated by intracoronary streptokinase (SK) infusion. Ejection fraction (EF) increased slightly, from 52% ± 13% before admission SK intervention to 58% ± 13% immediately after early recanalization of the completely obstructed coronary vessel (p < 0.0005, n = 68), while local wall motion usually improved. Immediately improved LV function appears to be the result of early reperfusion and/or decreased LV afterioad. In 55 chronic (long-term follow-up) post-AMI (2 to 4 weeks after successful early SK reperfusion) patients, repeat anglography revealed late reocclusion of the infarct vessel in nine patients. Chronic EF was not significantly different from pre-SK intervontion EF in these nine patients with late reocclusion, whereas in the remaining 46 patients with persistent patency, EF increased mildly from 52% ± 13% (before SK intervention) to 56% ± 16% (in long-term recanalization) (p < 0.025). Ventricular loading conditions were not different at pre-SK intervention angiography and chronic anglography. EF rose modestly from 51% ± 14% to 57% ± 18% in the 23 patients recanalized on follow-up, in whom pre-SK intervention angiography revealed collaterals to the infarcting area (p < 0.025), whereas there was no EF change in the 23 chronically recanalized patients without pre-SK collaterals. In the eight patients recanalized at late follow-up, who had preadmission chest pain for less than 3 hours and successful SK reperfusion within 4 hours of symptom onset (group A), EF increased significantly from 51% ± 12% to 65% ± 6% (p < 0.025). In the 25 chronically recanalized patients admitted 3 to 6 hours after onset of chest pain, in whom SK reperfusion was successful (group B), EF was unchanged at late study. In the 13 chronically recanalized patients with preadmission chest pain lasting longer than 6 hours, in whom SK reperfusion was successful (group C), EF increased from 52% ± 13% before SK intervention to 56% ± 16% at late study (p < 0.025). Pre-SK intervention angiography revealed collateral vessels to the infarct area in 69% of group C patients but in only 42% of patients in groups A and B. These findings suggest that the critical interval for myocardial salvage, as well as for early and long-term improvement of LV function by SK reperfusion at admission, is 4 hours after onset of chest pain in the majority of AMI patients. This time interval may be longer in patients with well-developed collateral supply to the region of the acute infarct.     

Acute myocardial infarction: Sex-related differences in prognosis

In 641 patients (535 men and 106 women) with acute myocardial infarction (AMI), a mortality of 16.63% was recorded among the former and one of 42.45% among the latter. No significant difference was observed in the age groups up to 40 years, in the group from 41 to 55 years, and in those over 71; the difference between percentages (17.09 vs 38.23) was instead statistically significant (p < 0.01) in patients in the age group from 56 to 70 years. This difference was significant (p < 0.01 or 0.001) with regard to mortality in diabetics (21.36% vs 46.34%), nondiabetics (13.09% vs 30.36%), hypertensives (19.72% vs 37.70%) and nonhypertensives (12.86% vs 36.11%), as well as in patients with previous infarction (33.36% vs 81.82%) and in those with first infarction (12.18% vs 31.39%). Since this phenomenon does not seem related to any particular feature of infarction nor to a particular predisposition to specific causes of death, the reasons for such severe prognosis in women require clarification.     

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

BACKGROUND: The relevance of the atrial coronary anatomy in the pathogenesis of atrial arrhythmias and atrioventricular (AV) block complicating acute myocardial infarction (AMI) remains unclear. OBJECTIVES: We evaluated the location of the infarct-related coronary lesion relative to the principal atrial branches (ie, sinoatrial nodal, AV nodal, left atrial circumflex) in 454 patients with ST-elevation AMI in the CAPTORS II trial. METHODS: Patients underwent systematic 60-minute postfibrinolytic angiograms, and coronary anatomy was correlated with evidence of atrial arrhythmias and AV block on sequential electrocardiograms. RESULTS: Patients with either sinoatrial nodal or left atrial circumflex compromise (n = 34) had a higher incidence of "early" (ie, up to 90 minutes postfibrinolysis) atrial arrhythmias vs those without (23.5% vs 7.1%; P = .004). Patients with AV nodal compromise (n = 207) had a higher incidence of "early" AV block vs those without (12.1% vs 3.6%; P = .001). CONCLUSION: These findings support the etiological role of acute atrial ischemia in the development of early atrial arrhythmias and AV block complicating AMI.     

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.     

Right ventricular involvement with acute inferior wall myocardial infarction identifies high risk of developing atrioventricular nodal conduction disturbances

In 67 consecutive patients with inferior wall acute myocardial infarction (AMI), 99m-technetium pyrophosphate scintigraphy was performed 36 to 72 hours after the onset of chest pain to detect right ventricular (RV) involvement. All patients were continuously monitored during at least 3 days to detect rhythm and conduction disturbances. In 29 patients RV involvement was diagnosed by scintigraphy. None of these 29 patients showed clinical signs of right-sided heart failure. Fourteen of the 19 patients showing atrioventricular (AV) nodal condution disturbances in the setting of inferior AMI also had RV involvement. Therefore, the incidence of high-degree AV nodal block in patients with RV involvement (14 of 29 patients) was 48% compared to only 13% (5 of 38) in patients with inferior AMI without RV involvement.     

Prognostic implications of complicated ventricular arrhythmias early after hospital discharge in acute myocardial infarction: A serial ambulatory electrocardiography study

To assess the prevalence and prognostic implications of complicated ventricular ectopic depolarizations (VEDs) after hospital discharge in patients with acute myocardial infarction (AMI), we obtained serial 24-hour Holter recordings in 85 patients during the first 6 weeks after AMI. Recordings were obtained during two coronary care unit time intervals, two hospital ward time intervals, and during four weekly time intervals after discharge. Complicated VEDs were defined as unifocal $\text{VEDs ≥}\text{10}\text{1000}$ beats for 24 hours, multiform VEDs, pairs, or ventricular tachycardia. At 1 year follow-up, there were nine cardiac deaths (six sudden deaths and three deaths from recurrent AMI). The mean left ventricular ejection fraction at discharge in the cardiac death patients was 29 ± 12% (sudden death patients 24 ± 11% and AMI death patients 40 ± 6%) compared to 49 ± 13% in the survivors (p < 0.001). Patients with complicated VEDs at discharge (2 weeks after AMI) or during the first 4 weeks after discharge (3 to 6 weeks after AMI) were significantly more likely to have sudden death at follow-up compared to patients without complicated VEDs. Of the six sudden death patients, four (66%) had complicated VEDs at discharge compared to 18 of 68 survivors (26%) (p < 0.05). One of there patients who died of recurrent AMI had complicated VEDs. No Holter data were obtained at hospital discharge in eight of the survivors. Of the six patients with sudden death at follow up, six (100%) had complicated VEDs on three or more 24-hour Holter recordings during the first 4 weeks after discharge compared to 21 of 76 survivors (28%) (p < 0.001). We conclude that AMI patients with complicated VEDs at discharge or during the first 4 weeks after discharge are at increased risk for sudden death at follow-up. Moreover, the persistence or appearance of complicated VEDs early after discharge in AMI patients may be a marker of continued or acquired myocardial electrical instability and for increased risk of sudden death at follow-up.