cardiopulmonary

Cardiopulmonary exercise stress testing can be useful in a variety of ways, particularly for Preventive Cardiology and Preventive Cardio-oncology. The test helps to assess for levels of fitness, causes of functional limitation, and evidence of ischemia. Test results can be used to counsel individuals, guide exercise prescriptions, and reassure, encourage, and motivate individuals for lifestyle modification and behavior change.

The exercise ECG portion of the test gives information regarding evidence of ischemia, exercise capacity, and adequacy of heart rate response, and response of blood pressure to exercise. The information of this portion of the test can help to determine whether there are any high-risk cardiac features that need to be addressed, such as evidence of ischemia or hypotensive response to exercise. Limited heart rate response is also useful to help determine whether rate-limiting medications or pacemaker settings need to be adjusted. Often, when medications like metoprolol or pacemaker heart rate response are adjusted, this can improve the function and experience of patients who are previously limited by their heart rate during activity. The exercise capacity information given by the exercise ECG, such as excellent, good, average, below average, fair, or poor can give an indication of individuals’ ability to meaningfully, safely, and successfully pursue exercise. Oftentimes, some patients who have had prior cardiovascular events may shy away from moderate or intense exercise for fear of cardiovascular injury as a result of exertion. Pursuing an exercise ECG portion of the cardiopulmonary stress test can help individuals in such cases recognize that they can perform moderate or intense exercise safely without injuring their heart. The exercise capacity reported on the test can help these individuals see that their exercise or aerobic capacity is poor because of their hesitation to pursue moderate or intense exercise. This can be motivating for individuals to recognize that they can benefit from doing more and that they can do more safely. This is particularly the case for individuals who have experienced a cardiovascular event from spontaneous coronary artery dissection, which does not have many modifiable risk factors, and understandably leads to apprehension in young women diagnosed with this condition. However, the exercise ECG portion alone lacks several informative parameters important for patient care in Preventive Cardiology and Cardio-Oncology.

The specific addition to the test provided by the ‘cardiopulmonary’ portion involves oxygen consumption. If oxygen consumption (or VO2) is below average, limited, or poor, there can be several reasons for this. The most common reasons include cardiac impairment, pulmonary impairment, deconditioning, excess weight, and limited heart rate reserve. There are various parameters in the cardiopulmonary stress test results that will indicate whether deconditioning plays a role, whether BMI plays a role, whether cardiac impairment plays a role (in which case this could be due to low flow from systolic dysfunction or due to diastolic dysfunction or even heart rate), or whether pulmonary impairment plays a role (which could be of varied etiology). This addition to the test also helps patients to objectively see data supporting the suspicion that they have become deconditioned after a cardiovascular event or after cancer therapies. They get to see that the cancer therapies or their subsequent levels of activity following their cardiovascular event could currently or potentially affect their function, and may explain any current functional limitation or in fact set them up for functional limitation going forward. The test can also help patients see the effect of any excess weight on their compromised oxygen consumption. Given that cancer therapies for breast cancer, for example, will often include radiation, surgery, and chemotherapy that can injure the heart and/or the lungs, it is helpful to determine the suggested underlying causes of functional limitation as assessed by oxygen consumption in these patients who have had treatment involving the chest. Performing the cardiopulmonary stress test at baseline before treatment helps individuals see their level of fitness, deconditioning, weight effect, cardiac impairment, or pulmonary impairment, even before ever undergoing cancer therapy. Given that fitness levels and injuries to the heart or the lungs can be affected by cancer therapies, then repeating the test after therapies can show patients the change that has occurred as a response to therapies. This can be helpful for patient to have a sense of their original baseline and goals that they can work towards to supersede even that baseline. For individuals who are not going to undergo cancer therapies, obtaining a baseline also helps individuals with a sense of how much they could potentially achieve. Then, once they have achieved a particular goal, the test can be repeated to show the improvement and continue to inspire motivation. This objective collection of evidence and data that can be used for motivation, reassurance, counseling, and exercise prescription is all key for lifestyle modification and behavior change in Preventive Cardiology and Preventive Cardio-Oncology. Thus, for all these reasons and more cardiopulmonary stress testing will evolve to play a large role in Cardio-Oncology prehabilitation, habilitation, and rehabilitation^1,2,3, as we help individuals prepare for, experience well, and long outlive their cancer therapies.

References

https://earlycareervoice.professional.heart.org/preventive-cardio-oncology-the-rise-of-prehabilitation/. Accessed April 20, 2019.
Squires RW, Shultz AM, Herrmann J. Exercise Training and Cardiovascular Health in Cancer Patients. Curr Oncol Rep. 2018 Mar 10;20(3):27. doi: 10.1007/s11912-018-0681-2.
Gilchrist SC, Barac A, Ades PA, Alfano CM, Franklin BA, Jones LW, La Gerche A, Ligibel JA, Lopez G, Madan K, Oeffinger KC, Salamone J, Scott JM, Squires RW, Thomas RJ, Treat-Jacobson DJ, Wright JS; American Heart Association Exercise, Cardiac Rehabilitation, and Secondary Prevention Committee of the Council on Clinical Cardiology; Council on Cardiovascular and Stroke Nursing; and Council on Peripheral Vascular Disease. Cardio-Oncology Rehabilitation to Manage Cardiovascular Outcomes in Cancer Patients and Survivors: A Scientific Statement from the American Heart Association. Circulation. 2019 Apr 8:CIR0000000000000679. doi: 10.1161/CIR.0000000000000679. [Epub ahead of print].

Do you want to read something amazing, awesome, and interesting? The AHA recently published its latest Scientific Statement: Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease.

Cardiac arrest in the hospital is 10 times more common among children with congenital heart defects or other acquired heart conditions compared to children with healthy hearts, according to the statement published Monday in the journal Circulation. As a pediatric cardiac intensivist, I often find myself overthinking things when I go for my PALS or ACLS recertification. “Well, if the patient is having a pulmonary hypertensive crisis, then I’d actually do this also…” or “At this point, I would have already activated ECMO.” In all honesty, I don’t reach for my PALS card during a real-life resuscitation in the pediatric cardiac ICU anymore. Not because I don’t follow the guidelines – I am the first to admit that high-quality CPR is the cornerstone of resuscitation and my team has these algorithms streamlined and burned into the backs of our minds – but because I have so many other things going through my head for this patient population. (Does this baby have pacing wires? What vessels are patent? Is the shunt occluded? How will vasopressin affect this kid’s physiology? Has this chest tube been draining appropriately leading up to the arrest?) None of these things are specifically addressed in the AHA resuscitation guidelines, until now.

Bradley S. Marino, MD, MPP, MSCE, Professor of Pediatrics and Medical Social Sciences at the Northwestern University Feinberg School of Medicine and a Pediatric Cardiac Intensivist at Ann & Robert H. Lurie Children’s Hospital and Chair of the AHA Council on Cardiovascular Disease in the Young along with his expert colleagues on the AHA Congenital Cardiac Defects Committee have painstakingly taken the time to address the unique issues surrounding peri-resuscitation care and considerations for the high-risk pediatric cardiac population. “The new statement is meant to be a powerful tool for health care professionals to both improve survival in children with heart disease who have a cardiac arrest and prevent cardiac arrests from ever happening in these high-risk children,” said Dr. Marino. “This scientific statement is a critical supplement to the American Heart Association’s Pediatric Advanced Life Support Guidelines that has been long overdue,” Marino said.

I asked Dr. Marino what the most important thing was that the authors learned while putting together the statement. “Given the incidence of cardiac arrest in the pediatric cardiac population, activities to prevent cardiac arrest are very important. We need to do more to modify our present clinical care systems to minimize the incidence of cardiac arrest. In addition, we need to tailor our resuscitation strategies for children with cardiac disease. While the PALS recommendations are very helpful to resuscitate all children with cardiac arrest, more information was needed to address the special needs of the pediatric cardiac population.”

The statement reviews all of the stages of cardiopulmonary resuscitation (pre-arrest, during CPR, and post-resuscitation care) and the considerations for each stage of single-ventricle palliation, right- and left-sided heart disease, pulmonary hypertension, cardiomyopathies and myocarditis, and arrhythmias. They also speak to considerations related to patient age, patient location, ECPR, and all of the various pharmacologic agents that we use frequently in these patients.

As for Dr. Marino’s hopes for providers to take away after reading the statement, he says “Tailoring resuscitation is possible once providers understand the specific anatomy, physiology, and cardiopulmonary interaction that is present at each patient’s bedside.”

It’s definitely a long document to read through, but is a critical review for all providers who care for pediatric patients with heart disease, especially those of us in the ICU setting. Click here to read it.

David K. Werho, MD is an Assistant Clinical Professor at the University of California San Diego and a Pediatric Cardiac Intensivist at Rady Children’s Hospital – San Diego. His research focuses on pediatric cardiac ICU outcomes as well as interventions and curriculum development in medical education. He tweets @DWerho and contributes to the Pediatric Cardiac Intensive Care Society Newsletter as editor and contributor.

Preventive Cardio-Oncology: A Role For Cardiopulmonary Stress Testing

It’s Finally Here: New AHA Statement On Resuscitation In Pediatric Patients With Heart Disease And Comments From The Author