Amado Alejandro Baez, MD, said in a presentation at the 2022 scientific assembly of the American College of Emergency Physicians.
The patient arrived on day 20 after a radical cystoprostatectomy. He had driven 4 hours from another city for a urology follow-up visit. On arrival, he developed respiratory distress symptoms and presented to the emergency department, said Dr. Baez, professor of emergency medicine and epidemiology at the Medical College of Georgia/Augusta University and triple-board certified in EMS, emergency medicine, and critical care.
The patient developed a massive pulmonary embolism with acute cor pulmonale (right-sided heart failure). An electrocardiogram showed an S1Q3T3, demonstrating the distinctive nature of right ventricular failure, said Dr. Baez.
Research has demonstrated the differences in physiology between the right and left ventricles, he said.
Dr. Baez highlighted some of the features of right ventricle (RV) failure and how to manage it. Notably, the RV is thinner and less resilient. “RV failure patients may fall off the Starling curve,” in contrast to patients with isolated left ventricle (LV) failure.
RV pressure overload is associated with a range of conditions, such as pericardial disease, pulmonary embolism, acute respiratory distress syndrome, and pulmonary arterial hypertension. When combined with RV overload, patients may develop intracardiac shunting or coronary heart disease, Dr. Baez said. Decreased contractility associated with RV failure can result from sepsis, right ventricular myocardial infarction, myocarditis, and arrhythmia.
Dr. Baez cited the 2018 scientific statement from the American Heart Association on the evaluation and management of right-sided heart failure. The authors of the statement noted that the complicated geometry of the right heart makes functional assessment a challenge. They wrote that various hemodynamic and biochemical markers can help guide clinical assessment and therapeutic decision-making.
Increased RV afterload drives multiple factors that can ultimately lead to cardiogenic shock and death, said Dr. Baez. These factors include decreased RV oxygen delivery, decreased RV coronary perfusion, decreased systemic blood pressure, and low carbon monoxide levels. RV afterload also leads to decreased RV contractility, an increase in RV oxygen demand, and tension in the RV wall, and it may contribute to tricuspid valve insufficiency, neurohormonal activation, and RV ischemia.
Treatment strategies involve improving symptoms and stopping disease progression, said Baez. In its scientific statement, the AHA recommends steps for assessing RV and LV function so as to identify RV failure as soon as possible, he said. After excluding pericardial disease, the AHA advises diagnosis and treatment of etiology-specific causes, such as right ventricular MI, pulmonary embolism, and sepsis. For arrhythmias, it recommends maintaining sinus rhythm when possible and considering a pacemaker to maintain atrioventricular synchrony and to avoid excessive bradycardia.
In its statement, the AHA also recommends optimizing preload with right arterial pressure/central venous pressure of 8-12 mm Hg, said Dr. Baez. Preload optimization combined with afterload reduction and improved contractility are hallmarks of care for patients with RV failure.
Avoiding systemic hypotension can prevent sequelae, such as myocardial ischemia and further hypotension, he said.
Optimization of fluid status is another key to managing RV failure, said Dr. Baez. Right heart coronary perfusion pressure can be protected by maintaining mean arterial pressure, and consideration should be given to reducing the RV afterload. Other strategies include inotropic medications and rhythm stabilization.
In general, for RV failure patients, “correct hypoxia, hypercarbia, and acidosis and avoid intubation when possible,” he said. Extracorporeal membrane oxygenation (ECMO) may be an option, depending on how many mechanical ventilator settings need to be adjusted.
In a study by Dr. Baez and colleagues published in Critical Care Medicine, the authors presented a Bayesian probability model for plasma lactate and severity of illness in cases of acute pulmonary embolism. “This Bayesian model demonstrated that the combination of shock index and lactate yield superior diagnostic gains than those compare to the sPESI and lactate,” Dr. Baez said.
The care model needs to be specific to the etiology, he added. Volume management in congested pulmonary hypertension involves a “squeeze and diurese” strategy.
According to the Internet Book of Critical Care, for patients with mean arterial pressure (MAP) of 60 mm Hg, central venous pressure (CVP) of 25 mm Hg, renal perfusion pressure of 25 mm Hg, and no urine output, a vasopressor should be added to treatment, Dr. Baez said. In cases in which the MAP 75 mm Hg, the CVP is 25 mm Hg, the renal perfusion pressure is 50 mm Hg, and the patient has good urine output, vasopressors should be continued and fluid should be removed through use of a diuretic. For patients with a MAP of 75 mm Hg, a CVP of 12 mm Hg, and renal perfusion pressure of 63 mm Hg who have good urine output, the diuretic and the vasopressor should be discontinued.
Dr. Baez also reviewed several clinical studies of the utility of acute mechanical circulatory support systems for RV failure.
In two small studies involving a heart pump and a right ventricular assistive device, the 30-day survival rate was approximately 72%-73%. A study of 179 patients involving ECMO showed an in-hospital mortality rate of 38.6%, he said.
Overall, “prompt diagnosis, hemodynamic support, and initiation of specific treatment” are the foundations of managing RV failure, he concluded.
Dr. Baez disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.