Heart Failure After Right Ventricular Myocardial Infarction

[Treatment of cardiogenic shock due to right ventricular involvement]

The right ventricle is susceptible to changes in preload, afterload, and contractility. The answer is its dilation with dysfunction/acute failure; filling is limited to the left ventricle and cardiac output. Systemic venous congestion is retrograde to the right heart, it is involved in the genesis of cardiogenic shock due to right ventricle involvement. This form of shock is less well known than that which occurs due to left ventricular failure, therefore, treatment may differ. Once the primary treatment has been carried out, since no response is obtained, supportive treatment aimed at ventricular pathophysiology will be the next option. It is suggested to evaluate the preload for the reasoned indication of liquids, diuretics or even ultrafiltration. Restore or maintain heart rate and sinus rhythm, treat symptomatic bradycardia, arrhythmias that make patients unstable, use of temporary pacing or cardioversion procedures. Improving contractility and vasomotility, using vasopressors and inotropes, alone or in combination, the objective will be to improve right coronary perfusion pressure. Balance the effect of drugs and maneuvers on preload and/or afterload, such as mechanical ventilation, atrial septostomy and pulmonary vasodilators. And the increasing utility of mechanical support of the circulation that has become a useful tool to preserve/restore right heart function.

Mechanism of heart failure after myocardial infarction

Despite the widespread use of early revascularization and drugs to regulate the neuroendocrine system, the impact of such measures on alleviating the development of heart failure (HF) after myocardial infarction (MI) remains limited. Therefore, it is important to discuss the development of new therapeutic strategies to prevent or reverse HF after MI. This requires a better understanding of the potential mechanisms involved. HF after MI is the result of complex pathophysiological processes, with adverse ventricular remodeling playing a major role. Adverse ventricular remodeling refers to the heart's adaptation in terms of changes in ventricular size, shape, and function under the influence of various regulatory factors, including the mechanical, neurohormonal, and cardiac inflammatory immune environments; ischemia/reperfusion injury; energy metabolism; and genetic correlation factors. Additionally, unique right ventricular dysfunction can occur secondary to ischemic shock in the surviving myocardium. HF after MI may also be influenced by other factors. This review summarizes the main pathophysiological mechanisms of HF after MI and highlights sex-related differences in the prognosis of patients with acute MI. These findings provide new insights for guiding the development of targeted treatments to delay the progression of HF after MI and offering incremental benefits to existing therapies.

Evaluation of right-ventricular function by two-dimensional echocardiography and two-dimensional speckle-tracking echocardiography in patients with successful RCA CTO recanalization

OBJECTIVES

Chronic total occlusion (CTO) of the right coronary artery (RCA) is common in patients with coronary artery disease. Although revascularization techniques and success rates have improved significantly in recent years, there are still no studies investigating possible effects of successful recanalization of RCA CTO on the right-ventricular (RV) function. With this study, we aimed to evaluate RV function after recanalization of the RCA by two-dimensional transthoracic echocardiography (2DE) and additional two-dimensional speckle-tracking echocardiography (2DSTE).

METHODS AND RESULTS

Our analysis included 102 patients undergoing successful RCA CTO recanalization at the University Medical Center of Mainz. All patients underwent 2DE and 2DSTE to assess RV function before PCI procedure and 6 months after successful revascularization. We found an altered RV function in our collective at baseline assessed by 2DSTE with a significant improvement at 6 month follow-up (baseline RV free wall strain: - 20.7 [- 6.3 to - 32.0] % vs. - 23.4 [- 8.3 to - 39.3] % at follow-up, p < 0.001 and baseline RV global strain - 15.9 [- 6.0 to - 25.7] % vs. - 17.9 [- 7.0 to - 29.5] % at follow-up, p < 0.001).

CONCLUSION

RV function was altered in patients with RCA CTO and showed significant improvement after successful recanalization. We also noticed an improvement in patient-reported clinical symptoms. Our study suggests that CTO procedure is a beneficial treatment option in symptomatic patients with RCA CTO.

Levosimendan improves cardiac function, hemodynamics, and body inflammation in patients with acute myocardial infarction and heart failure

OBJECTIVE

To examine the effects of levosimendan on cardiac function, hemodynamics, and body inflammation of patients with acute myocardial infarction and heart failure.

METHODS

A retrospective analysis was conducted on 113 acute myocardial infarction patients with heart failure (admitted to Xianyang First People's Hospital from September 2018 to January 2022). According to the treatment plan, patients were categorized into a control group (n = 53) (treated with conventional diuresis and vasodilation) and observation group (n = 60) (treated with levosimendan in addition to the treatment of the control group). Indexes were compared between the two groups before and after treatment, including effectiveness rate, mean pulmonary arterial pressure (PAMP) and pulmonary capillary wedge pressure (PCWP). Left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular ejection fraction (LVEF) were monitored before and after treatment by color Doppler ultrasonography. Serum high-sensitivity C-reactive protein (hs-CRP) levels were measured before and after treatment. Logistic analysis was applied to screen independent factors affecting treatment efficacy. Adverse reactions and life quality after 6 months of treatment were compared between the two groups.

RESULTS

The overall response rate of the observation group was higher than that of the control group (P<0.05). Changes in PAMP and PCWP in the two groups before and after treatment were significantly different. Patients in the observation group had improved indicators compared with the control group (all P<0.05). After treatment, the cardiac function indexes and inflammation-related factors of the observation group were improved more than those of the control group (P<0.05). Patients in the observation group had a lower incidence of adverse reactions and a higher life quality 6 months after treatment compared to the control group (P<0.05). Diabetes and treatment regimen were independent risk factors affecting treatment efficacy by logistic regression analysis.

CONCLUSION

The administration of levosimendan helps improve cardiac function, hemodynamics, and body inflammation in patients with acute myocardial infarction and heart failure, with fewer adverse reactions and higher safety.

[Anatomy-physiology considerations for cardiogenic shock with right ventricular involvement]

Since the discovery of right ventricular infarction, interest in the characteristics of the right ventricle has been increasing. Right ventricular function is now known to be a predictor of mortality in different settings. The right ventricle is a low-pressure, high-compliance, high-volume chamber. To carry out its normal function, it is coupled to the pulmonary circulation and the left ventricle. In the face of acute changes in pressure, volume overload and ischemia, it dilates to adapt to its new load. Its manifestation may be ventricular dysfunction and/or failure that will progress to cardiogenic shock due to right ventricular involvement. Various entities may be the cause of acute dysfunction: right ventricular infarction (alterations in contractility due to ischemia) and high-risk pulmonary thromboembolism (increased afterload). Both share a similar ventricular pathophysiology and high mortality without treatment. Understanding anatomy and physiology, dysfunction and acute ventricular failure are important to define a convenient diagnosis and treatment oriented towards pathophysiology. In this first part, the anatomy and physiology, acute right ventricular dysfunction/failure and cardiogenic shock are taken into consideration, from the perspective of these two entities. In another paper, treatment aimed at cardiogenic shock due to right ventricular involvement will be reviewed.

Cardioprotective Effects of a Selective c-Jun N-terminal Kinase Inhibitor in a Rat Model of Myocardial Infarction

Activation of c-Jun N-terminal kinases (JNKs) is involved in myocardial injury, left ventricular remodeling (LV), and heart failure (HF) after myocardial infarction (MI). The aim of this research was to evaluate the effects of a selective JNK inhibitor, 11H-indeno [1,2-b]quinoxalin-11-one oxime (IQ-1), on myocardial injury and acute myocardial ischemia/reperfusion (I/R) in adult male Wistar rats. Intraperitoneal administration of IQ-1 (25 mg/kg daily for 5 days) resulted in a significant decrease in myocardial infarct size on day 5 after MI. On day 60 after MI, a significant (2.6-fold) decrease in LV scar size, a 2.2-fold decrease in the size of the LV cavity, a 2.9-fold decrease in the area of mature connective tissue, and a 1.7-fold decrease in connective tissue in the interventricular septum were observed compared with the control group. The improved contractile function of the heart resulted in a significant (33%) increase in stroke size, a 40% increase in cardiac output, a 12% increase in LV systolic pressure, a 28% increase in the LV maximum rate of pressure rise, a 45% increase in the LV maximum rate of pressure drop, a 29% increase in the contractility index, a 14% increase in aortic pressure, a 2.7-fold decrease in LV end-diastolic pressure, and a 4.2-fold decrease in LV minimum pressure. We conclude that IQ-1 has cardioprotective activity and reduces the severity of HF after MI.