Higenamine, a Dual Agonist for β1- and β2-Adrenergic Receptors Identified by Screening a Traditional Chinese Medicine Library
In Summary
A recent Chinese study has found an herbal compound that promises to treat chronic heart failure. Higenamine, an alkaloid found in monkshood, has been found to be a dual agonist for a receptor pathway that has been implicated in the late stages of heart disease. Monkshood has already been utilized in Chinese medicine and the isolation of higenamine is an exciting advancement for the therapeutic benefits this herb provides. Further studies are needed to confirm higenamine’s ability to treat chronic heart failure.
This study brings to light the number of herbal compounds used in eastern medicine that are not yet being utilized in western medicine. In the United States herbs are just now starting to be seriously researched for medicinal properties in a lab setting despite their importance in eastern medicine and home remedies. Extracts of naturally occurring compounds are finally coming to the forefront of medicine as the public looks for natural and sustainable remedies for everyday ailments, treatment-resistant disorders, and even cancer. The potential of these compounds deserves serious consideration in today’s medicine.
The study is available for review or download here
Sudden cardiac death associated to substances of abuse and psychotropic drugs consumed by young people- A population study based on forensic autopsies
In Summary:
A recent study out of Spain has revealed alarming trends among cases of sudden cardiac death associated with substances of abuse consumed by young people. Half of the 15-36-year-olds who suffered sudden cardiac death were found with illicit substances in their bodies, primarily cannabis, tobacco, and cocaine. Researchers found that although cannabis was the most common substance found in the deceased systems, cocaine and tobacco are known to have a stronger impact on the cardiovascular system and lead to ischemic heart disease, which is often the more acute causes of sudden death. It was also mentioned here that the duration of cannabis is far longer in the body than that of either tobacco or cocaine, and this duration may easily confuse people to associate it as a trigger for sudden death.
However, on the other hand, there are several tragic cases of young, otherwise heart-healthy individuals who have died with cannabis as the only substance discovered. Fortunately, these cases are extraordinarily rare, but unfortunately, no reproducible association has been established, so the mysterious concerns are not easily relieved or forgotten.
Dr. Caplan and the #MDTake:
While the return of medical cannabis to modern medical care seems to bring with it a return of appreciation for more naturalistic care, it is critical for us all to recognize that we still have much to learn. The tools and high standards of scientific evaluation have only recently been applied to cannabis, and there are reasonable arguments that the usual tools may not actually apply (for example, some are suggesting that the placebo effect, a cornerstone of randomized control trials may be a facet of effects related to the endocannabinoid system.)
For these, and a great many other unknowns, it is important for the discerning consumer to consult with trusted resources, including friends, family, scientists, and where possible, doctors, to ensure the appropriateness of use on an individual basis.
Article title: Atrioventricular Nodal Reentrant Tachycardia Triggered by Marijuana Use: A case report and review of the literature
Summary:
The effect of cannabis on the heart is not yet well-understood. This report highlights a case of one 40-year-old patient who had, an hour after smoking cannabis, a specific type of cardiac rhythm abnormality (arrhythmia) called atrioventricular nodal reentrant tachycardia (AVNRT). There is a physical component of this abnormality, an errant track where aberrant rhythms re-enter the heart and can cause rapid heartbeats (tachycardia.) In the discussion, the authors suggest that cannabis use, at higher doses, may stimulate the parasympathetic system, which happens to be involved in electrical current tracks in our heart. The authors further hypothesize that in susceptible people, as in this case, cannabis may affect this electrical pathway in the heart, and may disrupt a stable rhythm.
Dr Caplan and the #MDTake:
Abnormal heart rhythm disorders can be life-concerning conditions, however, there have only been 17 or so reported cases (see Table 1) of life-threatening cases in the medical literature. As it is exceedingly rare, it can be difficult to determine if cannabis is implicated or not.
Clinical Impressions:
Including rare, serious heart conditions, relatively benign circumstances, and conditions related to structural heart disease, arrhythmias are a relatively uncommon condition. Nevertheless, CED Clinic has seen many patients who have atrial fibrillation, a smaller but significant number of patients who have stable low or elevated heart rates, and a rare few with irregularly irregular abnormalities. Some patients have embraced cannabis while anticoagulated (helpful to reduce the risks of potentially dangerous clots), and some who are engaging with cannabis have been treated surgically. The approach to cannabis that most seem to prefer is a slow, gradually increasing dosage routine, where one can become accustomed to low doses, prior to advancing to something which may be more therapeutic, while minimizing the potential cardiac impact. Fortunately, to date, we have observed no grave repercussions that seemed caused, correlated or attributable to cannabis.
Article title: Acute Cardiovascular Effects of Marijuana Use
The Review:
The authors of this systematic review combed through multiple previously published studies, looking at the short-term cardiovascular effects of THC on the body. The cardiovascular effects they covered included: changes in blood pressure, heart rate, and blood flow to the brain (cerebrovascular circulation).
This review showed that for blood pressure, the results were undecided, as some studied showed a drop in blood pressure, while others did not. For heart rate, the studies showed an increase after consuming marijuana, but quantity and duration were not mentioned. As for blood flow to the brain, only one study showed a potential decrease while the others found no change. The THC percentage of the products used (mainly inhaled ones) ranged from 1.2% to 17.5%.
Dr Caplan and the #MDTake:
This limited review aims to evaluate the effects of THC on blood pressure, heart rate and blood flow to the brain, but it has important limitations. In terms of how the changes were recorded in the studies and the relevant amounts (of what is changing) were not mentioned. For instance, while the study did show that THC may increase heart rate in the short term, it is not clear what the relevance is, what risk this may poses to consumers if any. Past literature has shown that heart muscle can respond to specific cannabinoids, both in the lab and in animals trails. Several case studies have reported individuals with grave reactions, although these concerns have yet to be replicated in a controlled manner, nor correlated with any specific circumstances or components of cannabis. Toward a goal of maximizing safety, caution is likely warranted for those consuming cannabis with known cardiac risk factors (including heart dysfunction, blood pressure concerns, rhythm abnormalities, and others) particularly with regard to the consumption of high THC products.
Clinical Impressions:
Clinically, there is a distinct trend of people who have found heart rate effects with their cannabis use, mostly increased heart rates at the beginning of use (both when first beginning to consume cannabis as well as early on during an episode of consumption.) There seems to be a tolerance to the heart rate effects because many report that this effect wanes over time. There are a clear group of patients for whom cannabis lowers blood pressure, but also groups for who it either has no effect or increases blood pressure. The long-term trend again seems that tolerance plays a role in bringing all extremes to the middle ground. Regarding blood flow, there seems to be a clear increase in local blood flow with topicals and, at least among CED Clinic patients, no observable relationship between cannabis use and blood flow, from a macroscopic perspective.
