Stressing the Cardiovascular Implications of Mind-Body Heart Connections

The seminal discovery of the amygdala’s contribution to emotional health more than a half-century ago (1), helped to uncover the psychophysiological interplay between the mind, body and heart. Although much remains to be learned, it is clear that the many connections linking the mind, body, and heart are rich, varied, and highly complex and coordinated. We now have a greater appreciation of the mechanistic underpinnings through which mental stress promotes alterations in neurotransmitter and stress hormone expression, heightens systemic inflammation, and impacts the development and severity of multiple risk factors, ultimately predisposing persons to cardiovascular disease (CVD) (2). As elegantly elaborated upon in the scientific statement by Levine et al., (3) the authors provide compelling evidence in support of psychological health assessments as an integral component of CVD risk evaluation.

In conceptualizing the most devastating sequalae that acute emotional stress inflicts on the heart, two unique circumstances stand out. The first is a natural disaster, such as an earthquake, which produces unexpectedly high rates of sudden cardiac death and/or hospitalization for myocardial infarction (MI) that commonly occur within hours of the unexpected event (4). The second is a personal disaster, where the sudden and unanticipated death of a loved one results in excessive catecholamine release, resulting in myocardial stunning and a left ventricular systolic appearance that resembles a Japanese octopus pot or takotsubo (5). While these occurrences are rare, they highlight acute emotional turmoil as an important contributor to adverse cardiovascular outcomes. Nevertheless, as emphasized in the scientific statement, the more common scenario faced by patients are not acute but, rather, chronic day-to-day stressors that can result in elevated blood pressure, endothelial dysfunction, tachycardia, arrhythmias, stress eating, insulin resistance, disordered sleep, and other physiological derangements that adversely impact cardiovascular function. Whether they occur in the workplace or as a consequence of social isolation or post-traumatic stress disorder, prolonged psychological distress contributes to a sizeable rise (40-60%) in the likelihood of a primary or recurrent CVD related event.

With respect to personality traits, the scientific statement reaffirms that chronic anger and hostility, a prominent feature of the “Type A” personality, is associated with an approximate 20-25% increase in incident and, often, premature CVD. Similarly, increases in the risk of CVD has also been linked with chronic anxiety (~35-70%), depression (30-45%) and pessimism, or a sense of hopelessness (up to 2-fold). Taken together, if negative stressors that accompany daily life are ignored, denied, or insufficiently addressed, then a series of coordinated maladaptive biological changes including endothelial dysfunction, oxidative stress, prothrombotic tendency, and increased systemic inflammation develop to promote atheromatous vascular disease.

In an effort to counteract the potentially devastating consequences of chronic emotional stress, the scientific statement points to a number of positive emotional traits. These traits include optimism, a sense of purpose, as well as happiness and emotional vitality/well-being, all of which correlate with an approximately 20-35% reduction in CVD risk. Consequently, self-improvement programs may be particularly useful for patients who are chronically stressed. For example, in a study where relaxation practices incorporated meditation, yoga and prayer, baseline assessment of subjects without prior experience in these practices exhibited reduced expression of genes that downregulate inflammation and insulin sensitivity while displaying a relatively high expression of genes promoting inflammation and insulin resistance (regulated by the nuclear transcription factor NF-κB). (6) However, after a 2-month training period, the heat map for gene expression demonstrated a switch in the production of these atherosclerotic and metabolic biomarkers. That is, meditation and relaxation coincided with upregulation of anti-inflammatory and insulin function genes, as well as improvements in mitochondrial and immune system function, energy metabolism, and telomere maintenance in concert with the reduced expression of genes promoting inflammation and insulin resistance. Of particular interest was that the benefits observed after this relatively short training period was similar to the heat map of subjects who engaged in meditation chronically and who had practiced relaxation training for many years (6). These results suggest that even when there is a long history of chronic stress, engaging in positive psychosocial practices can beneficially alter the genetic expression of atherothrombotic biomarkers in a relatively brief period of time.

As emphasized in the scientific statement, most of the data generated to date with regard to the cardiovascular implications of mind-body-heart connections are based on associations rather than causality. Because the risk of MI is pronounced in the setting of internal strife and emotional distress (7), a large-scale randomized clinical trial would help to determine the extent to which promotion of positive psychological practices effectively attenuates CVD risk. In addition to the tools outlined in the scientific statement, music and laughter-based interventions might also be useful to incorporate due to their salutary effects on parasympathetic tone and endothelial function as evidenced by improved vasoreactivity (8-10). The demonstration that positive psychological practices reduce CVD events would provide the impetus for health care professionals to incorporate mind-body heart connections as part of a comprehensive strategy focused on optimizing cardiovascular health, beyond traditional CVD risk factors.