Complicated Acute Myocardial Infarction: Heart Failure, Shock, Mechanical Complications

Aneurysm and pseudoaneurysm of the left ventricle

The severity of myocardial infarction lies in its complications. Certainly, there was a significant decrease in their impact thanks to the improvement of medical care and advent of early reperfusion methods, but there is still a considerable rate of complications that pose diagnostic and therapeutic problems. Among them, there are left ventricular aneurysm and pseudoaneurysm. These two complications are relatively rare, their diagnosis and treatment are often difficult. We have attempted to review the existing literature and discuss the characteristic findings of each entity.

Assessment Framework for Recognizing Clinical Deterioration in Patients With ACS Undergoing PCI

TOPIC

Patients with acute coronary syndrome undergoing primary percutaneous coronary intervention are at risk of clinical deterioration that results in similar general signs and symptoms regardless of its cause. However, specific causes and forms of clinical deterioration are associated with key differences in assessment findings. Focused clinical assessments using a modified primary survey enable nurses to rapidly identify the cause and form of clinical deterioration, facilitating targeted treatment.

CLINICAL RELEVANCE

Clinical deterioration during percutaneous coronary intervention is associated with increased mortality and morbidity. Previous studies identified nursing inconsistencies when recognizing clinical deterioration, with inconsistent collection of cues and prioritization of cues related to cardiac performance over more sensitive indicators of clinical deterioration.

PURPOSE OF PAPER

To describe a framework to help nurses optimize physiological cue collection to improve recognition of clinical deterioration during periprocedural care of patients undergoing percutaneous coronary intervention for unstable acute coronary syndrome.

CONTENT COVERED

Literature analysis revealed 7 forms of clinical deterioration in patients undergoing percutaneous coronary intervention: coronary artery occlusion, stroke, ventricular rupture, valvular insufficiency, lethal cardiac arrhythmias, access-site and non-access-site bleeding, and anaphylaxis. Evidence for the pathophysiology, incidence, severity, and clinical features of each form of clinical deterioration is identified. A framework is proposed to help nurses conduct highly focused patient assessments, enabling prompt recognition of and response to the specific forms of clinical deterioration that occur in patients undergoing percutaneous coronary intervention.

Mechanical Circulatory Support in Cardiogenic Shock due to Structural Heart Disease

Despite advances in cardiovascular care, managing cardiogenic shock caused by structural heart disease is challenging. Patients with cardiogenic shock are critically ill upon presentation and require early disease recognition and rapid escalation of care. Temporary mechanical circulatory support provides a higher level of care than current medical therapies such as vasopressors and inotropes. This review article focuses on the role of hemodynamic monitoring, mechanical circulatory support, and device selection in patients who present with cardiogenic shock due to structural heart disease. Early initiation of appropriate mechanical circulatory support may reduce morbidity and mortality.

Survival after sequential mechanical complications of acute myocardial infarction, complicated with heparin-induced thrombocytopenia and multiple organ failure: report of a case

BACKGROUND

Ventricular wall rupture and acute mitral regurgitation due to papillary muscle rupture post-acute myocardial infarction are rare and dramatic mechanical complications. The operative mortality of both complications remains extremely high but this is the only treatment which has greatly improved the prognosis.

CASE PRESENTATION

We describe the course of a patient, who survived after left ventricular free wall rupture two days post-acute myocardial infarction. He underwent left ventricular rupture repair plus two coronary artery bypass grafting. On the fifth postoperative day he developed papillary muscle rupture and acute mitral valve regurgitation. He was reoperated as an emergency case for mitral valve replacement. The patient sustained numerous complications, such as renal failure, heparin-induced thrombocytopenia, sepsis, acute respiratory distress syndrome, and multiple organ failure. He was on continuous venous-venous hemofiltration for one week and underwent a tracheostomy on the ninth postoperative day. He remained on a ventilator for three weeks. The patient survived, was discharged home after six weeks, and remains in very good condition on follow-up so far.

CONCLUSION

The operative mortality of both complications remains high but this is the only treatment which improves the prognosis. Surviving both events is rare and few cases have been reported in the literature. This case highlights the necessity of careful echocardiographic examination in any patient presented with post-myocardial infarction new onset of hemodynamic instability. Identification of a single site of rupture does not eliminate the possibility of additional ruptures in the papillary muscle and intraventricular septum, and transesophageal echocardiography should be used to search for these entities. Although repair of each of these complications carries a high mortality, failure to address them will almost certainly result in death. Using standard surgical techniques, including preoperative intraaortic balloon pump insertion and careful postoperative management, successful outcome is possible.

Survival after simultaneous left ventricular free wall, papillary muscle, and ventricular septal rupture

Cardiac rupture is a catastrophic complication of acute myocardial infarction. The three potential sites of rupture are the left ventricular free wall, interventricular septum, and papillary muscle. Without rapid surgical correction, each of these complications typically leads to cardiogenic shock, multiorgan failure, and death. Postmortem analysis has identified a small number of cases in which myocardial infarction led to rupture at more than one of these sites; however, there are no reports of survival from such an event. We report a case involving rupture at all three sites in the same patient, emphasizing the importance of transesophageal echocardiography and surgical management.

Cardiogenic shock due to acute severe mitral regurgitation complicating acute myocardial infarction: a report from the SHOCK Trial Registry. SHould we use emergently revascularize Occluded Coronaries in cardiogenic shocK?

OBJECTIVES

Our objective was to define the outcomes of patients with cardiogenic shock (CS) due to severe mitral regurgitation (MR) complicating acute myocardial infarction (AMI).

BACKGROUND

Methods for early identification and optimal treatment of such patients have not been defined.

METHODS

The SHOCK Trial Registry enrolled 1,190 patients with CS complicating AMI. We compared 1) the cohort with severe mitral regurgitation (MR, n = 98) to the cohort with predominant left ventricular failure (LVF, n = 879), and 2) the MR patients who underwent valve surgery (n = 43) to those who did not (n = 51).

RESULTS

Shock developed early after MI in both the MR (median 12.8 h) and LVF (median 6.2 h) cohorts. The MR patients were more often female (52% vs. 37%, p = 0.004) and less likely to have ST elevation at shock diagnosis (41% vs. 63%, p < 0.001). The MR index MI was more frequently inferior (55% vs. 44%, p = 0.039) or posterior (32% vs. 17%, p = 0.002) than that of LVF and much less frequently anterior (34% vs. 59%, p < 0.001). Despite having higher mean LVEF (0.37 vs. 0.30, p = 0.001) the MR cohort had similar in-hospital mortality (55% vs. 61%, p = 0.277). The majority of MR patients did not undergo mitral valve surgery. Those undergoing surgery exhibited higher mean LVEF than those not undergoing surgery; nevertheless, 39% died in hospital.

CONCLUSIONS

The data highlight opportunities for early identification and intervention to potentially decrease the devastating mortality and morbidity of severe post-myocardial infarction MR.

Echocardiography's Role in Cardiogenic Shock After Acute Myocardial Infarction

Cardiogenic shock is an emergent condition that requires immediate diagnosis. Assessment and evaluation of potential complications that often accompany shock must also be made. These complications may be seen individually or in concert. Echocardiography has emerged in the last two decades as the single most important procedure in this effort. The authors reviewed four cases of cardiogenic shock after acute myocardial infarction: two with ventricular septal rupture, one with papillary muscle rupture, and one with severe global left ventricular dysfunction. Each patient was evaluated emergently with echocardiography. Results were compared with electrocardiography, arteriography, right heart catheterization studies, and surgical reports.

Recombinant growth hormone: a new cardiovascular drug therapy

GH has an important role in normal cardiovascular physiologic functioning, working indirectly through effects on IGF-1. An excess or deficiency of GH causes an increased rate of cardiovascular disease, including cardiomyopathy. A relative GH deficiency in older subjects may also increase cardiovascular morbidity and mortality risk. In replacement doses, GH can enhance myocardial contractility; can decrease peripheral vascular resistance; and can reduce total cholesterol and LDL-cholesterol values and fibrinogen and PAI levels. These effects of GH, coupled with the ability to improve skeletal muscle function and reduce adiposity, make it an attractive treatment for patients with CHF and a potential maintenance drug for elderly people. Clinical trials, including studies with GHRH that may reduce the adverse effects of GH therapy, such as hyperglycemia and hypertension, are now in progress.

Percutaneous cardiopulmonary support for the management of catastrophic mechanical complications of acute myocardial infarction

Acute papillary muscle rupture and ventricular septal rupture following myocardial infarction are associated with high mortality. We describe the use of cardiopulmonary support to resuscitate two patients, each with one of the above conditions. Early recognition and rapid deployment of CPS were critical to successful outcome.

Transesophageal echocardiography and concurrent coronary angiography for the rapid assessment of papillary muscle rupture

Echocardiography with color flow imaging is valuable for identifying mechanical complications of myocardial infarction. Transesophageal echocardiography is useful for critically ill patients in whom transthoracic imaging is often insufficient. A case of papillary muscle rupture is presented in which transesophageal echocardiography was performed concurrently with coronary angiography. The detailed information obtained from two-dimensional and color flow imaging eliminated the need for diagnostic right heart catheterization and left ventriculography. Transesophageal echocardiography used in this manner can facilitate expeditious surgical management.

Pathogenesis and management of acute heart failure and cardiogenic shock: role of inotropic therapy

Patients with acute heart failure or cardiogenic shock following myocardial infarction have a high mortality. The first priority is to salvage any remaining viable myocardium, either by thrombolytic agents or, if necessary, by coronary angioplasty. A mechanical cause for the heart failure or shock needs to be excluded. Thereafter, the optimal therapeutic regimen needs to be chosen on the basis of each patient's hemodynamic profile. Patients can be broadly classified into three groups: (1) patients with a high left ventricular filling pressure (> 18 mm Hg) and a cardiac index < 2.2 L/min/m2 but systolic arterial pressure > 100 mm Hg; (2) patients with a systolic arterial pressure < 90 mm Hg, left ventricular filling pressure > 18 mm Hg, and cardiac index < 2.2 L/min/m2; and (3) patients with an elevated right ventricular filling pressure (> 10 mm Hg) and cardiac index < 2.2 L/min/m2 and a systolic arterial pressure < 100 mm Hg. Patients in the first subset usually require the use of vasodilator therapy and/or dobutamine. The choice of inotropic agent in patients in the second hemodynamic subset depends on the degree of systemic hypotension; dopamine is usually preferred initially because it increases arterial pressure in addition to improving cardiac output. Once the systemic blood pressure has been stabilized, dobutamine can be substituted for superior augmentation of cardiac output and its additional beneficial effects on the left ventricular filling pressure. Norepinephrine may be indicated in cases of severe systemic hypotension. Patients in hemodynamic subset 3, ie, right ventricular infarction, are treated with volume expansion and dobutamine. Use of nonpharmacologic means of circulatory support, eg, intra-aortic balloon pump or left ventricular assist device may also be required in any of these subsets.