Factors associated with pericardial effusion in acute Q wave myocardial infarction

Prognostic relevance of pericardial effusion in STEMI patients treated by primary percutaneous coronary intervention: a 10-year single-centre experience

BACKGROUND

Pericardial effusion is frequent in the acute phase of ST-segment elevation myocardial infarction. However, its prognostic role in the era of primary percutaneous coronary intervention is not completely understood.

METHODS

We investigated the association between pericardial effusion, assessed by transthoracic echocardiography, and survival in a large cohort of ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention, enrolled in the Trieste primary percutaneous coronary intervention registry from January 2007 to March 2017. Multivariable analysis and a propensity score approach were performed.

RESULTS

A total of 1732 ST-segment elevation myocardial infarction patients were included. Median follow-up was 45 (interquartile range 19-79) months. Pericardial effusion was present in 246 patients (14.2%). Thirty-day all-cause mortality was similar between patients with and without pericardial effusion (7.8% vs. 5.4%, P=0.15), whereas crude long-term survival was worse in patients with pericardial effusion (26.2% vs. 17.7%, P≤0.01). However, at multivariable analyses the presence of pericardial effusion was not associated with long-term mortality (hazard ratio 1.26, 95% confidence interval 0.86-1.82, P=0.22). Matching based on propensity scores confirmed the lack of association between pericardial effusion and both 30-day (hazard ratio 1, 95% confidence interval 0.42-2.36, P=1) and long-term (hazard ratio 1.14, 95% confidence interval 0.74-1.78, P=0.53) all-cause mortality. Patients with pericardial effusion experienced a higher incidence of free wall rupture (2.8% vs. 0.5%, P<0.0001) independently of the entity of pericardial effusion.

CONCLUSIONS

In acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention, the onset of pericardial effusion after ST-segment elevation myocardial infarction is not independently associated with short and long-term higher mortality. Free wall rupture has to be considered rare compared to the fibrinolytic era and occurs more frequently in patients with pericardial effusion, suggesting a close monitoring of these patients in the early post-primary percutaneous coronary intervention phase.

Established and novel pathophysiological mechanisms of pericardial injury and constrictive pericarditis

This review article aims to: (1) discern from the literature the immune and inflammatory processes occurring in the pericardium following injury; and (2) to delve into the molecular mechanisms which may play a role in the progression to constrictive pericarditis. Pericarditis arises as a result of a wide spectrum of pathologies of both infectious and non-infectious aetiology, which lead to various degrees of fibrogenesis. Current understanding of the sequence of molecular events leading to pathological manifestations of constrictive pericarditis is poor. The identification of key mechanisms and pathways common to most fibrotic events in the pericardium can aid in the design and development of novel interventions for the prevention and management of constriction. We have identified through this review various cellular events and signalling cascades which are likely to contribute to the pathological fibrotic phenotype. An initial classical pattern of inflammation arises as a result of insult to the pericardium and can exacerbate into an exaggerated or prolonged inflammatory state. Whilst the implication of major drivers of inflammation and fibrosis such as tumour necrosis factor and transforming growth factor β were foreseeable, the identification of pericardial deregulation of other mediators (basic fibroblast growth factor, galectin-3 and the tetrapeptide Ac-SDKP) provides important avenues for further research.

Pericardium: The Forgotten Space During Acute Myocardial Infarction

BACKGROUND

Acute pericardial pathologies, such as pericardial effusion, pericarditis, and cardiac tamponade, have been reported rarely in patients presenting as ST-elevation myocardial infarction (STEMI). We present a series of 3 patients with STEMI, where an undiagnosed pericardial effusion led to pericardial tamponade and subsequent cardiocirculatory collapse.

CASE REPORTS

This is a case series of 3 patients, all women, aged 72, 64, and 54 years who presented to the emergency department with chest pain or syncope and were found to have STEMI with hemodynamic instability. They were taken to the catheterization laboratory for urgent coronary revascularization requiring mechanical circulatory support (intra-aortic balloon pump or impella). During catheterization, all 3 patients were diagnosed with large pericardial effusion using hemodynamic parameters and bedside transesophageal echocardiogram. Commonly ignored, pericardial tamponade and acute large pericardial effusion can be the cause of cardiocirculatory collapse. Two of the 3 patients survived with aggressive interventions requiring pericardial drains, long-term mechanical circulatory support, and effective postoperative rehabilitation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: It is important for treating clinicians, including emergency physicians, intensivist, and cardiologist, to consider the differential of a cardiac tamponade due to a pericardial effusion as a potential cause for hypotension in patients with an acute STEMI.

Effect of Pericardial Effusion Complicating ST-Elevation Myocardial Infarction as Predictor of Extensive Myocardial Damage and Prognosis

Pericardial effusion (PE) is a common complication following ST-elevation myocardial infarction (STEMI). However, the frequency and prognostic relevance of PE complicating STEMI are unknown. Aim of this study was to investigate the exact incidence, infarct characteristics, and the prognostic impact of moderate-to-large PEs detected by cardiac magnetic resonance (CMR) in patients with acute reperfused STEMI. In total, 780 patients with STEMI reperfused by angioplasty (<12 hours after symptom onset) were enrolled in this CMR study at 8 centers. CMR was completed in median 3 days after infarction using a standardized protocol. Central core laboratory-masked analysis for the presence of moderate-to-large PE was performed. The primary clinical end point was the occurrence of major adverse cardiac events (MACE) defined as composite of all-cause death, reinfarction, and new congestive heart failure within 12 months after the index event. A moderate-to-large PE was detected in 183 patients (24%). Patients with moderate-to-large PEs had significantly larger infarcts, less myocardial salvage, a larger extent of microvascular obstruction, higher incidence of intramyocardial hemorrhage, and more pronounced left ventricular dysfunction (p <0.001 for all). Significant predictors of a moderate-to-large PE were age, Thrombolysis in Myocardial Infarction flow before percutaneous coronary intervention, and infarct size. MACE rates were significantly higher in the PE group (p = 0.003) and a moderate-to-large PE was identified as a significant independent predictor for MACE (hazard ratio 3.12, 95% confidence interval 1.49 to 6.81; p = 0.003) together with Thrombolysis in Myocardial Infarction risk score and left ventricular ejection fraction. In conclusion, a moderate-to-large PE complicating STEMI is a common finding (almost 25%) and related to more severe infarcts with subsequent significantly increased MACE rates during 1-year follow-up. Consequently, a moderate-to-large PE is a marker of poor outcome in patients with STEMI.

Predictive Factors of Pericardial Effusion After a First Acute Myocardial Infarction and Successful Reperfusion

The aim of the study was to identify the determinants of pericardial effusion (PE) after a first myocardial infarction (MI). Cardiac magnetic resonance enables early analysis of multiple post-MI parameters; 193 patients with a first ST-elevation MI admitted to the Angers University Hospital (France) were enrolled prospectively. Cardiac magnetic resonance was performed at baseline (median of 5 days [4 to 7]) and repeated at a 3-month follow-up to investigate left ventricular (LV) volumes, LV ejection fraction, infarct size, microvascular obstruction (MVO), systolic wall stress (SWS), and PE presence and extent. A 1-year follow-up was also performed. Overall, 113 patients (58.5%) showed a PE with a median size of 31.6 ± 24.0 ml in the event that a PE was present. Patients with PE typically presented larger initial infarct sizes and LV volumes, and higher SWS, with more depressed LV ejection fraction and more frequent MVO and pleural effusions. Patients with PE exhibited higher rates of heart failure during hospitalization. At follow-up, there was no relevant PE, with no pericardiocentesis required. The multivariate analysis revealed SWS (odds ratio [OR] 1.092 [95% CI 1.007 to 1.184], p = 0.042), infarct size (OR 1.048 [95% CI 1.014 to 1.083], p = 0.003), and MVO extent (OR 1.274 [95% CI 1.028 to 1.579], p = 0.018) to be independent predictors for PE presence and volume. One patient died of LV free wall rupture during initial hospitalization, with only "small" PE found. In conclusion, infarct size, MVO, and SWS were independently related to PE presence and volume. Post-MI PE was found in 58.5% of cases, being regressive at follow-up. Among these patients with early reperfusion and optimal medical therapy, PE volume did not seem to be related to future clinical events.

Predictors of moderate-to-severe pericardial effusion, cardiac tamponade, and electromechanical dissociation in patients with ST-elevation myocardial infarction

Occurrence of moderate-to-severe pericardial effusion (PE; ≥10 mm), cardiac tamponade (CT), and sudden electromechanical dissociation (EMD) was investigated in 4,361 patients with ST-elevation myocardial infarction from 1993 to 2011 in 3 different periods: 1993 to 2000 (n: 1,488); 2001 to 2008 (n: 1,844); and 2009 to 2011 (n: 1,014). Their predictors, including the use of no reperfusion therapy (n: 1,186), thrombolysis (n: 1,607), or primary percutaneous coronary intervention (PPCI, n: 1,562), were also evaluated. Incidence of PE (8.7%, 6.8%, and 5.0%), CT (5.0%, 2.9%, and 1.9%), and EMD (3.7%, 1.7%, and 1.0%), declined over the 3 periods as did mortality (12.0% 8.2%, and 5.9%) with different rates of thrombolytic therapy (52%, 37%, and 14%) and PPCI (7%, 38%, and 76%; all p<0.001). In patients treated without reperfusion therapy, thrombolysis, and PPCI, incidence of PE (12.0%, 5.7%, and 4.3%), CT (6.0%, 3.0%, and 2.2%), and EMD (4.1%, 2.2%, and 0.8%) was different as was mortality (14.4%, 8.3%, and 5.9%; all p<0.001). Independent predictors of PE were lateral infarction (odds ratio [OR] 4.09, 95% confidence interval [CI] 2.57 to 6.49), increasing age (OR 1.05, 95% CI 1.04 to 1.07), number of electrocardiographic leads involved (OR 1.34, 95% CI 1.23 to 1.45), and admission delay (OR 1.01, 95% CI 1.01 to 1.02). Increasing ejection fraction (OR 0.97, 95% CI 0.96 to 0.98), thrombolysis (OR 0.53, 95% CI 0.37 to 0.75), and PPCI (OR 0.35, 95% CI 0.25 to 0.50), however, were protectors (all p<0.001). Lateral infarction, age, number of leads involved, ejection fraction, thrombolytic therapy, and PPCI were also predictors/protectors of CT and EMD. In conclusion, PE, CT, and EMD rates in patients with ST-elevation myocardial infarction have objectively fallen in the last 2 decades, and their predictors are lateral site, increasing age, number of leads involved, and lack of reperfusion therapy. Late hospital admission is also a relevant predictor of PE.

Regional pericarditis: a review of the pericardial manifestations of acute myocardial infarction

Regional pericarditis has been described in several settings, but occurs most frequently after transmural myocardial infarction. While the diagnosis remains elusive, it must be considered in all patients with recurrent chest pain following acute myocardial infarction (AMI). Pericarditis classically presents with positional chest pain, a pericardial friction rub, diffuse ST-segment elevation, and PR depression, but regional ECG changes associated with infarction-associated pericarditis sometimes exist. Given the magnitude and frequency of AMI, it is imperative to be aware of the myriad of pericardial manifestations of myocardial injury. An illustrative case and a comprehensive review of the literature will be provided.

Pathophysiology of acute myocardial infarction

More than 80% of acute myocardial infarcts are the result of coronary atherosclerosis with superimposed luminal thrombus. Uncommon causes of myocardial infarction include coronary spasm, coronary embolism, and thrombosis in nonatherosclerotic normal vessels. Additionally, concentric subendocardial necrosis may result from global ischemia and reperfusion in cases of prolonged cardiac arrest with resuscitation. Myocardial ischemia shares features with other types of myocyte necrosis, such as that caused by inflammation, but specific changes result from myocyte hypoxia that vary based on length of occlusion of the vessel, duration between occlusion and reperfusion, and presence of collateral circulation.

Clinical factors associated with persistent pericardial effusion after successful primary coronary angioplasty

STUDY OBJECTIVE

To evaluate the incidence and clinical factors related to the persistence of infarct-associated pericardial effusion (PE) after primary angioplasty.

DESIGN

Consecutive case-series analysis.

SETTING

Coronary care unit in a university hospital.

PATIENTS

Three hundred ninety-one consecutive patients with acute myocardial infarction (AMI) who underwent successful primary percutaneous transluminal coronary angioplasty (PTCA) at hospital admission.

INTERVENTIONS

Coronary angiography and primary PTCA on hospital admission and serial echocardiography.

MEASUREMENTS AND RESULTS

The status of coronary flow before and after primary PTCA was evaluated by coronary angiography at hospital admission, while PE was studied by echocardiography within 24 h of admission and 1 month after the onset of AMI. PE was present in the acute phase in 76 patients (19%), and patients with PE had a significantly higher incidence of in-hospital death than those without PE (11% vs 2%, p < 0.001). Among 68 patients who had PE in the acute phase and underwent echocardiography 1 month later, PE persisted to 1 month after the onset of AMI (persistent PE) in 26 patients (38%). Patients with persistent PE had a significantly higher incidence of pericardial rub (p = 0.010), Killip class > 1 (p = 0.025), no reflow after PTCA (p = 0.026), lower incidence of collaterals (p = 0.024), and tended to have higher peak creatine kinase (CK) [p = 0.05] levels than those with transient PE. When five variables (peak CK, collaterals, no reflow, pericardial rub, and Killip class > 1) were used in the multivariate analysis, pericardial rub (p = 0.023; odds ratio [OR], 5.45), absence of collaterals (p = 0.011; OR, 0.16), and Killip class > 1 (p = 0.027; OR, 3.80) were the significant variables related to persistent PE.

CONCLUSIONS

PE remains a relatively common complication of AMI even in the era of reperfusion therapy and is associated with increased mortality. Furthermore, the presence of a pericardial rub, Killip class > 1, and absence of collateral flow in the early phase of the infarct are associated with persistence of the PE to 1 month after the onset of AMI.

Value of myocardial contrast echocardiography for predicting left ventricular remodeling and segmental functional recovery after anterior wall acute myocardial infarction

OBJECTIVE

We sought to study the value of microvascular perfusion assessed by myocardial contrast echocardiography in predicting left ventricular remodeling after anterior wall acute myocardial infarction.

METHODS

In 31 patients myocardial contrast echocardiography was performed up to 48 hours after acute myocardial infarction with determination of end-diastolic and end-systolic volumes, wall-motion score index, and myocardial perfusion score index (MPSI) at rest and under dobutamine stress at 6 months. Patients were classified into remodeling group (RG) (n = 19) and non-RG (n = 12), and, according to number of segments without opacification, reflow (< or =2 segments, n = 15) and no-reflow (>2 segments, n = 16) groups.

RESULTS

Wall-motion score index (1.84 +/- 0.22 vs 1.64 +/- 0.3; P =.049), MPSI (1.53 +/- 0.25 vs 1.26 +/- 0.17; P =.006), and number of segments without contrast (3.11 +/- 2.23 vs 1.08 +/- 1.38; P =.018) were higher in RG than in non-RG. End-diastolic and end-systolic volumes, and wall-motion score index, increased significantly in RG at 6 months and decreased in non-RG. MPSI increased in RG (1.53 +/- 0.25-1.66 +/- 0.21; P =.011) and was the only independent predictor of left ventricular remodeling (odds ratio = 1.8; 95% confidence interval = 1.15-2.82; P =.010). No-reflow group presented 27.8 +/- 19.9% of segments with resting functional recovery or contractile reserve, and reflow group presented 69.9 +/- 31.2% (P <.001).

CONCLUSION

MPSI obtained 48 hours after acute myocardial infarction is an independent predictor of left ventricular remodeling. Patients with two or fewer segments without opacification revealed a better prognosis of resting ventricular function and contractile reserve.

Nature and progression of pericardial effusion in patients with a first myocardial infarction: relationship to age and free wall rupture

BACKGROUND

Left ventricular free wall rupture (FWR) usually develops within the first days of acute myocardial infarction (AMI) without warning, but it is uncertain whether a mild pericardial effusion might herald this complication.

METHODS

A 2-dimensional echocardiogram (2DE) was performed in patients with first AMI with (1149) or without (324) ST-segment elevation within 2 days. A second 2DE was performed 2 to 4 days later in 300 patients, 100 with and 200 without an initial mild PE (3-9 mm), and in those with initial moderate-severe PE (> or =10 mm) (MSPE) or who developed hypotension or died.

RESULTS

The first 2DE showed mild PE in 177 patients and MSPE in 51 patients, whereas a late (>2 days) MSPE occurred in 27 with a second routine 2DE, 15 (15%) with and 12 (6%) without initial mild PE (P =.01). Fourteen additional patients, 5 of 77 (6%) with and 9 of 1045 (1%) without initial PE, presented with hypotension and late MSPE (P <.002). Of 92 patients with MSPE, 90 had ST-segment elevation (98%), 60 had tamponade (65%), and 38 died of FWR or were operated on (41%). Results of pericardiocentesis performed in 64 patients were positive in 58, with hemopericardium in 57 (98%). Multivariant analysis showed mild PE on first 2DE and age of >60 years as the only independent predictors of late MSPE or late tamponade.

CONCLUSIONS

Mild PE within the first 2 days in patients aged >60 years with a first ST-segment elevation AMI is associated with an increased risk of late MSPE. Moreover, in this setting MSPE is most frequently associated with hemopericardium, and two thirds of these patients may develop tamponade/FWR.

Clinical significance of coronary flow to the infarct zone before successful primary percutaneous transluminal coronary angioplasty in acute myocardial infarction

STUDY OBJECTIVE

To assess the effect of coronary flow to the infarct zone before primary coronary angioplasty on hospital complications in patients with acute myocardial infarction (MI).

DESIGN

Consecutive case series analysis.

SETTING

Coronary-care unit in a university hospital.

PATIENTS

Two hundred sixty-four consecutive patients with ST-elevation acute MIs who had successful primary percutaneous transluminal coronary angioplasty.

INTERVENTIONS

Coronary angiography on hospital admission and serial echocardiography.

MEASUREMENTS AND RESULTS

The status of infarct-related artery flow before primary angioplasty was evaluated on hospital admission. Left ventricular wall motion and pericardial effusions were studied by echocardiography. One hundred ninety patients had total occlusions (Thrombolysis in Myocardial Infarction [TIMI] flow grade, 0 to 1) in the infarct-related artery (group 1), and 74 patients had antegrade flow (TIMI flow grade, 2 to 3) [group 2] before undergoing primary angioplasty procedures. When group 1 was subdivided into two groups (for the presence and absence of collateral flow), the patients with total occlusions and no collateral flow had a higher incidence of left ventricular aneurysmal wall motion (11% vs 1%, respectively; p = 0.03) and pericardial friction rub (15% vs 3%, respectively; p = 0.03) than did those in group 2. Moreover, those patients with total occlusions and no collateral flow had higher incidences of pericardial effusion (34% vs 17%, respectively; p = 0.02; and 34% vs 9%, respectively; p < 0.01) and in-hospital mortality (8% vs 1%, respectively; p = 0.04; and 8% vs 1%, respectively; p = 0.06) than did those patients in the other two groups.

CONCLUSIONS

Despite successful primary angioplasty, the absence of antegrade flow in the infarct-related artery and collateral flow to the infarct zone before angioplasty resulted in a higher incidence of in-hospital complications.

Pericardial Effusion as a Consequence of Acute Myocardial Infarction

Pericarditis is a common complication of acute myocardial infarction (MI). Its incidence during the first few days after acute MI is 24%-43% when echocardiographic criteria are used, whereas the frequency of clinical pericarditis is much less (from 5% for all acute MIs to 21% for anterior Q wave MIs). Clinical, electrocardiographic findings are discussed. Effusions are mostly small, and the resolution is frequently slow, lasting 1-18 months. Tamponade is extremely rare in the absence of cardiac rupture. Q wave MIs (especially anterior) are more frequently accompanied by pericardial effusion. The prognostic significance of echocardiographically proved pericarditis is questionable.

Pericardial effusion after primary percutaneous transluminal coronary angioplasty in first Q-wave acute myocardial infarction

To evaluate the incidence and clinical significance of infarction-associated pericardial effusion in patients with successful primary percutaneous transluminal coronary angioplasty, we studied 214 consecutive patients with a first Q-wave acute myocardial infarction. Based on 9 clinical variables, multivariate analysis was performed to determine the important variables related to the occurrence of pericardial effusion. Pericardial effusion was detected by echocardiography in 45 patients (21%); pericardial rub (p <0.001), number of advanced asynergic segments (p <0.001), ventricular aneurysmal motion (p = 0.03), and pulmonary capillary wedge pressure (p = 0.04) were found to be the important variables related to pericardial effusion. Among 45 patients with pericardial effusion, 29 patients with no pericardial rub had significantly higher pulmonary capillary wedge pressure than those with pericardial rub, whereas 16 patients with pericardial rub had a higher incidence of angiographic no reflow and ventricular aneurysmal motion than those without pericardial rub. Patients with pericardial effusion and a pericardial rub had a higher mortality rate than those without pericardial effusion (19% vs 3%; p = 0.02). Thus, pericardial effusion is still a relatively common clinical finding after primary percutaneous transluminal coronary angioplasty, and those with pericardial effusion and a pericardial rub were associated with more severe transmural myocardial damage and higher in-hospital mortality.

Frequency of pericardial friction rub ("pericarditis") after direct percutaneous transluminal coronary angioplasty in Q-wave acute myocardial infarction

The clinical significance of infarct-associated pericarditis was examined in 201 consecutive patients with acute Q-wave myocardial infarction with successful direct percutaneous transluminal angioplasty. A pericardial rub was a reliable clinical sign of extensive myocardial damage in patients with direct angioplasty.

Pericardial involvement during the course of myocardial infarction. A long-term clinical and echocardiographic study

STUDY OBJECTIVE

This study investigated the long-term course of infarct-related pericarditis and pericardial effusion. Focus was given to the following issues: incidence and timing of pericarditis and pericardial effusion during the acute phase and 3 years follow-up, size, hemodynamic and clinical consequences of effusions, and potential risk of thrombolytic or anticoagulant therapy in patients with pericardial effusion.

PATIENTS AND STUDY DESIGN

Serial echocardiographic examinations were performed in 192 consecutive patients with first myocardial infarction during the acute phase (day 1, 5, 10, 21) and during 3 years' follow-up (year 1, 2, and 3 after infarction). The follow-up was 100%. Clinical, angiographic, and autopsy data were analyzed.

RESULTS

Pericardial effusion was detected at least once during serial echocardiographic examinations in 82 of 192 patients (43%). The incidence in different subgroups (with or without thrombolysis, open or closed artery at 3 weeks, infarction in left anterior descending, left circumflex, or right coronary artery perfusion bed) was similar. Most (48%) effusions were first detected on the fifth day, and most (50%) disappeared between days 21 and 365. However, in nine patients, the effusion persisted beyond 1 year (up to 3 years in three patients). Only systolic separation of pericardial layers was detected in 59% of effusions, circular effusion in 3.6% of all effusions. No cardiac tamponade developed. Heart failure or death complicated 49% of infarctions with pericardial involvement and 16% of infarctions without effusion (p < 0.01). Mortality alone was 8% among patients without effusion and 15% among those with more than minimal effusion (not significant).

CONCLUSIONS

Pericardial effusion can be detected by serial echocardiographic examinations in 43% of myocardial infarctions. It appears during the initial 5 days and disappears slowly during several weeks to several months. Anticoagulant and thrombolytic therapy does not increase the frequency or the size of effusions.

T wave changes consistent with epicardial involvement in acute myocardial infarction. Observations in patients with a postinfarction pericardial effusion without clinically recognized postinfarction pericarditis

OBJECTIVES

This study was designed to evaluate the presence or absence of atypical T wave evolution in patients with a postinfarction pericardial effusion but without clinically recognized postinfarction pericarditis. A second purpose was to evaluate the frequency of atypical T wave evolution in a previous study of postinfarction pericarditis.

BACKGROUND

Electrocardiographic (ECG) criteria involving the evolution of the T wave after an acute myocardial infarction were recently described in patients with regional postinfarction pericarditis. Atypical T wave evolution was found to have a sensitivity of 100% and a specificity of 77% for clinically recognized regional postinfarction pericarditis with or without a pericardial effusion.

METHODS

The hospital records and serial ECGs of 20 patients with clinically recognized postinfarction pericarditis (Group I) were reviewed. The records and serial ECGs of 20 additional patients with a postinfarction pericardial effusion without clinically recognized postinfarction pericarditis (Group II) were also examined. The type of postinfarction T wave pattern, typical or atypical, was recorded in both groups.

RESULTS

All 20 patients in Group I had atypical T wave evolution. Among the 20 patients in Group II, every patient also had atypical T wave evolution. Fifteen percent of all 40 patients with atypical T wave evolution had a non-Q wave infarction with definite or inferred postinfarction pericarditis.

CONCLUSIONS

The high sensitivity of atypical T wave evolution in diagnosing regional postinfarction pericarditis was confirmed. However, similar T wave alterations were also observed when a postinfarction pericardial effusion existed in the absence of clinically recognized pericarditis. Fifteen percent of patients with atypical T wave evolution had a non-Q wave infarction with definite or inferred pericardial involvement. Thus, the presence of atypical T wave evolution may be a more sensitive indicator of a transmural infarction than the development of a Q wave.

Clinical significance of pericardial effusion in Q-wave inferior wall acute myocardial infarction

To assess the clinical significance of pericardial effusion in Q-wave inferior wall acute myocardial infarction, 185 consecutive patients were examined by means of electrocardiogram, echocardiogram and hemodynamic monitoring. A pericardial effusion was present in 44 patients and was absent in 141 patients. Electrocardiographic right ventricular infarction (> or = 1 mm of ST-segment elevation and Q wave in V4R) was detected in 54 patients, with 20 patients having pericardial effusion. Patients with pericardial effusion had significantly more left ventricular segments with advanced asynergy, lower cardiac output, higher pulmonary artery wedge pressure and higher incidence of right ventricular infarction than those without pericardial effusion. There were 17 in-hospital deaths. Although there was no significant difference in the mortality rate between patients with and without right ventricular infarction, a significantly higher hospital mortality rate was observed in patients with pericardial effusion compared to those without it (23 vs 5%). Pericardial effusion was selected with age and pulmonary artery wedge pressure as important variables associated with hospital mortality by the discriminant analysis. Patients who developed pericardial effusion, regardless of right ventricular infarction, had more extensive myocardial damage, and hence, pericardial effusion was one of the predictors of increased hospital mortality.

Clinical significance of PQ segment depression in acute Q wave anterior wall myocardial infarction

OBJECTIVES

This study was designed to evaluate the clinical significance of PQ segment depression and to examine the frequency of PQ segment depression in infarction-associated pericarditis.

BACKGROUND

PQ segment deviation is almost as characteristic as the classic ST segment deviation and is detected in most patients with pericarditis. However, the incidence and clinical characteristics of PQ segment depression in acute myocardial infarction are not defined.

METHODS

Three hundred four consecutive patients with acute Q wave anterior wall myocardial infarction were examined carefully by auscultation, electrocardiogram, echocardiogram and chest roentgenogram. The diagnosis of pericarditis was made on the basis of pericardial rub detected by more than two observers during the 1st 3 days after hospital admission. At least 0.5 mm of PQ segment depression from the TP segment observed for > 24 h in both limb and precordial leads was considered diagnostic of PQ segment depression.

RESULTS

A pericardial rub was present in 65 patients (21%) and absent in 239 patients. PQ segment depression was detected in both limb and precordial leads in 30 patients (10%): 18 patients with pericardial rub and 12 patients without pericardial rub. On the basis of five clinical variables, multivariate analysis was performed to determine the important variables related to the occurrence of PQ segment depression. Pericardial rub was selected with left ventricular segments with advanced asynergy as a significant factor related to PQ segment depression. There were 31 in-hospital deaths, and a significantly higher hospital mortality rate was observed in patients with PQ segment depression (23% vs. 9%).

CONCLUSIONS

Although PQ segment depression was observed in a minority of patients with infarction-associated pericarditis, it was one of the clinical signs of larger infarct size and increased hospital deaths.

Clinical significance of pericardial effusion associated with pericarditis in acute Q-wave anterior myocardial infarction

To elucidate the incidence and clinical factors related to the occurrence of pericardial effusion in infarction-associated pericarditis, 303 consecutive patients with their first Q-wave anterior myocardial infarction were examined carefully by means of auscultation, echocardiography, chest radiography, and hemodynamic monitoring. During the first 3 days, a pericardial rub was detected in 65 patients and was absent in 238 patients. Among the 65 patients with pericardial rub, pericardial effusion was present in 27 patients (group 1) and was absent in 38 patients (group 2). Although there were no significant differences in cardiac output, pulmonary artery wedge pressure and right atrial pressure between the two groups, patients in group 1 had significantly more left ventricular segments with advanced asynergy and higher radiographic scores (diffuse interstitial infiltrate or alveolar infiltrate) compared with those in group 2. Thus, pericardial effusion and increased extravascular lung water in infarction-associated pericarditis were not caused by left ventricular failure but by other mechanisms reflecting a larger infarct.

Disturbance of pulmonary gas exchange in patients with acute myocardial infarction-associated pericardial effusion

To elucidate the effect of pericardial effusion on pulmonary gas exchange in patients with infarction-associated pericardial effusion, 294 consecutive patients with their first Q-wave anterior wall acute myocardial infarction were examined carefully by echocardiography, chest radiography and hemodynamic monitoring. A pericardial effusion was detected in 77 patients and was absent in 217 (group 1). Of the 77 patients with pericardial effusion, it was mild in 57 (group 2) and moderate in 20 (group 3). Patients with pericardial effusion (groups 2 and 3) had significantly greater pulmonary artery wedge pressure and more left ventricular segments with advanced asynergy than did those in group 1. Although there were no significant differences in pulmonary artery wedge pressure and number of left ventricular segments with advanced asynergy between groups 2 and 3, group 3 had significantly greater right atrial pressure, alveolar arterial oxygen difference and incidence of high radiographic score. Thus, accumulation of pericardial effusion to a moderate amount may contribute to the greater incidence of increase in extravascular lung water, and disturbance of pulmonary gas exchange.

Factors associated with atrial fibrillation in Q wave anterior myocardial infarction

To elucidate the role of inflammatory and hemodynamic factors in the genesis of atrial fibrillation in acute myocardial infarction, 228 patients with a first Q wave anterior myocardial infarction were studied. Forty-nine patients had pericarditis (detection of pericardial rub by careful auscultation), and 36 patients had echocardiographically demonstrated hydropericardium (presence of pericardial effusion without pericardial rub). During the first 3 days after admission, transient episodes of atrial fibrillation were observed in 10 patients (20%) with pericarditis (group 1), 15 patients (42%) with hydropericardium (group 2), and 20 patients (14%) without pericarditis and hydropericardium (group 3). Although there was no significant difference in the incidence of atrial fibrillation between groups 1 and 3, patients in group 2 had a significantly higher incidence of atrial fibrillation than those in groups 1 and 3. Pulmonary capillary wedge pressure and the number of advanced asynergic segments were found to be the important factors discriminating the three groups by multivariate analysis. Therefore atrial fibrillation after acute Q wave anterior infarction was not related to the inflammatory infiltration involving the atria but to the increase in atrial pressure resulting from hemodynamic change caused by more extensive myocardial damage.

Pericardial effusion after intravenous recombinant tissue-type plasminogen activator for acute myocardial infarction

The effect of thrombolytic therapy on the frequency, time course and sequelae of pericardial effusion after myocardial infarction are unknown. A prospective, serial, 2-dimensional echocardiographic study of patients with myocardial infarction who received recombinant tissue-type plasminogen activator (rt-PA) was undertaken to address this issue. The study population comprised 52 of the 112 patients enrolled in the first Thrombolysis and Angioplasty in Myocardial Infarction trial at Duke University Medical Center. Enrollment in the serial echocardiography protocol was determined by equipment and support staff availability. Complete echocardiographic studies were performed within 90 minutes after initiation of thrombolytic therapy (day 0), and on days 1, 3 and 6. Patients undergoing serial echocardiography did not differ in demographic or clinical characteristics from those who did not. Pericardial effusion was present in 3 of 38 patients (8%) at day 0, in 2 of 44 (5%) at day 1, in 8 of 43 (19%) at day 3, and in 10 of 42 (24%) at day 6. By day 6, 3 of 10 pericardial effusions were moderate in size, 1 of 10 was large and the remainder were small. No patients developed echocardiographic or hemodynamic signs of cardiac tamponade. The prevalence and time course of pericardial effusion among patients with acute myocardial infarction who received rt-PA in this study are similar to observations reported in earlier studies in which patients did not receive thrombolytic therapy. Adverse sequelae of pericardial effusion after thrombolytic therapy are rare.

Usefulness of a pericardial friction rub after thrombolytic therapy during acute myocardial infarction in predicting amount of myocardial damage. The TAMI Study Group

To evaluate the clinical incidence and outcomes of patients with pericarditis after thrombolytic therapy, 810 patients were prospectively studied during acute myocardial infarction (AMI). Pericarditis was defined as the presence of a pericardial friction rub during the hospital course. Only 5% of patients developed a rub during AMI, a low percent compared with that in the prethrombolytic era. A pericardial friction rub more often occurred in the setting of an anterior wall AMI. Patients with, compared to those without, a pericardial friction rub had lower ejection fractions (45 vs 51%, p = 0.002); worse regional left ventricular function (-3.2 vs 2.7, standard deviation per chord); higher in-hospital mortality (15 vs 6%, p = 0.056); a higher frequency of power failure (83 vs 57%); a higher frequency of anterior wall location of the AMI (53% of cases, p = 0.002); and a higher frequency of 3-vessel disease. Therefore, although the frequency of a pericardial friction rub was low (5%) compared with that in the prethrombolytic era, its occurrence denotes more extensive myocardial damage with a worse clinical outcome. Perhaps with successful reperfusion of the infarct-related vessel, transmural myocardial necrosis is prevented and with it the development of pericarditis. Cardiac tamponade did not occur clinically in any patient who developed a pericardial friction rub.