Pericardial involvement in acute myocardial infarction in the post-thrombolytic era: clinical meaning and value

Atrial and ventricular strain using cardiovascular magnetic resonance in the prediction of outcomes of pericarditis patients: a pilot study

OBJECTIVE

Our study aimed to explore with cardiovascular magnetic resonance (CMR) the impact of left atrial (LA) and left ventricular (LV) myocardial strain in patients with acute pericarditis and to investigate their possible prognostic significance in adverse outcomes.

METHOD

This retrospective study performed CMR scans in 36 consecutive patients with acute pericarditis (24 males, age 52 [23-52]). The primary endpoint was the combination of recurrent pericarditis, constrictive pericarditis, and surgery for pericardial diseases defined as pericardial events. Atrial and ventricular strain function were performed on conventional cine SSFP sequences.

RESULTS

After a median follow-up time of 16 months (interquartile range [13-24]), 12 patients with acute pericarditis reached the primary endpoint. In multivariable Cox regression analysis, LA reservoir and LA conduit strain parameters were all independent determinants of adverse pericardial diseases. Conversely, LV myocardial strain parameters did not remain an independent predictor of outcome. With receiving operating characteristics curve analysis, LA conduit and reservoir strain showed excellent predictive performance (area under the curve of 0.914 and 0.895, respectively) for outcome prediction at 12 months.

CONCLUSION

LA reservoir and conduit mechanisms on CMR are independently associated with a higher risk of adverse pericardial events. Including atrial strain parameters in the management of acute pericarditis may improve risk stratification.

CLINICAL RELEVANCE STATEMENT

Atrial strain could be a suitable non-invasive and non-contrast cardiovascular magnetic resonance parameter for predicting adverse pericardial complications in patients with acute pericarditis.

KEY POINTS

• Myocardial strain is a well-validated CMR parameter for risk stratification in cardiovascular diseases. • LA reservoir and conduit functions are significantly associated with adverse pericardial events. • Atrial strain may serve as an additional non-contrast CMR parameter for stratifying patients with acute pericarditis.

Diagnosis and Management of Pericardial Disease

The pericardium serves many important functions but is not essential for life. Pericardial heart disease comprises only pericarditis and its complications, tamponade and constriction, and congenital lesions. However, the pericardium is affected by virtually every category of disease. Thus the critical care physician is likely to encounter the patient with pericardial disease in a variety of settings, either as an isolated phenomenon or as a complication of a variety of systemic disorders, trauma, or certain drugs. Despite exhaustive etiological lists, the cause of pericardial heart disease is often never identified. This article reviews the diagnosis and management of acute and chronic pericarditis with an emphasis on those areas of greatest interest to the intensivist.

The prevalence and outcome of effusive constrictive pericarditis: a systematic review of the literature

There is sparse information on the epidemiology of effusive constrictive pericarditis (ECP). The objective of this article was to review and summarise the literature on the prevalence and outcome of ECP, and identify gaps for further research. The prevalence of ECP ranged from 2.4 to 14.8%, with a weighted average of 4.5% [95% confidence interval (CI) 2.2-7.5%]. Sixty-five per cent (95% CI: 43-82%) of patients required pericardiectomy regardless of the aetiology. The combined death rate across the studies was 22% (95(CI: 4-50%). The prevalence of ECP is low in non-tuberculous pericarditis, while pericardiectomy rates are high and mortality is variable. In this review, of 10 patients identified with tuberculous ECP, only one presumed case had a definite diagnosis of ECP. Appropriate studies are needed to determine the epidemiology of ECP in tuberculous pericarditis, which is one of the leading causes of pericardial disease in the world.

The metamorphosis of myocardial infarction following coronary recanalization

The "metamorphosis" of acute myocardial infarction (AMI) in terms of pathological features and complications in the reperfusion era is herein discussed. Typically, the AMI following coronary artery recanalization is characterized by frequent subendocardial location, since a prompt coronary lumen recanalization is able to prevent the transmural progression of myocardial necrosis from the endocardium towards the epicardium. Transmural AMI may develop when recanalization occurs late (>6 hours) or is not effective (persistent coronary occlusion). Moreover, reperfused AMI frequently appears reddish because of interstitial haemorrhage, which is thought to be caused by vascular cell damage with leakage of blood out of the injured vessels. Hemorrhage occurs always within the area of necrosis and it is significantly related to the infarct size and to the coronary occlusion time. At histology, typical features of reperfused AMI consist of contraction band necrosis and interstitial hemorrhage. Moreover, a more pronounced inflammatory cellular response is visible within the necrotic area when comparing reperfused with non-reperfused AMI. Reperfusion after prolonged coronary occlusion is also associated with secondary impairment of microcirculatory flow ("no-reflow" phenomenon), that is due to endothelial swelling, luminal obstruction and external compression but may also be aggravated by distal embolization. Finally, the reperfused AMI with its typical subendocardial, non-transmural location, is characterized by a lower incidence of expansive remodelling and related complications, in terms of cardiogenic shock, myocardial rupture, aneurysm and pseudoaneurysm formation and thromboembolism. Moreover, pericardial involvement is a rare occurrence. Unfavorable mechanical consequences of intramyocardial haemorrhage could consist in increased myocardial stiffness, propensity to wall rupture and delayed healing process. However, prospective in vivo large-scale studies in patients with reperfused AMI are needed to assess the prognostic value of hemorrhagic AMI in terms of morbidity and mortality. The knowledge and correct interpretation of these findings at post-mortem by the general and forensic pathologists is of great importance, to provide useful information to the clinicians.

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.

Acute pericarditis in the recovery phase of transient left ventricular apical ballooning syndrome (takotsubo cardiomyopathy)

A 64-year-old woman was admitted because of persistent chest pain and ST-elevation in the precordial and inferior leads on electrocardiogram. Emergent coronary angiography demonstrated that there was no obstruction, and left ventriculography showed apical akinesis and basal hyperkinesis. She was diagnosed with takotsubo cardiomyopathy. Chest pain subsided within the day of admission followed by T-wave inversion on electrocardiogram. Nevertheless, chest pain and ST-elevation reappeared late on the third hospital day, accompanied by fever and small amounts of pericardial and pleural effusions. Under the administration of nonsteroidal anti-inflammatory drug, the inflammation lessened. This is the first report of acute pericarditis in the recovery phase of takotsubo cardiomyopathy.

Post-Myocardial Infarction Pericarditis

Post-myocardial infarction pericarditis occurs in approximately 5% to 6% of patients who receive thrombolytic agents. It should be suspected in any patient with pleuropericardial pain. A pericardial friction rub may or may not be present. Differentiation of pericarditis from recurrent angina may be difficult, but a careful history and evaluation of serial electrocardiograms can help distinguish the two entities. Dressler's syndrome, pericarditis that occurs at least 1 week following myocardial infarction, is now exceedingly rare. Most cases of pericarditis have a benign course; however, because pericarditis is associated with larger infarcts, overall long-term mortality rate is increased. Rare complications include hemopericardium, cardiac tamponade, and constrictive pericarditis. Therapy is directed toward relief of pain, which usually responds well to nonsteroidal anti- inflammatory agents (eg, aspirin or ibuprofen).

Electrocardiographic manifestations: acute myopericarditis

Acute, or so-called "dry," myopericarditis occurs in the presence of diffuse inflammation of the pericardial sac and superficial epicardium from a multitude of infectious and inflammatory processes. This inflammation results in a current of myocardial injury resulting from the epicardial irritation manifested by a number of electrocardiographic findings. Classically, the electrocardiographic changes have been described as an evolution through several distinct stages involving ST segment elevation with PR segment depression, normalization of the ST segment abnormality with T wave inversion, and eventual normalization of the electrocardiogram over a period of days to several weeks. The following discussion focuses on the electrocardiographic manifestations of acute myopericarditis and includes findings useful in establishing the diagnosis as well as distinguishing the disease from other syndromes, particularly acute myocardial infarction.

Inflammatory disorders of the heart. Pericarditis, myocarditis, and endocarditis

The emergency physician frequently sees patients with cardiac complaints. Too often, ischemic heart disease is overwhelmingly considered to the exclusion of other diagnostic possibilities such as inflammatory cardiac disorders. These disorders can cause considerable discomfort, have long-term implications, or lead to more serious cardiac disorders. Emergency physicians must have a practical understanding of the diagnostic evaluation and therapeutic approach to patients with inflammatory cardiac disorders.