The Cardiac Conundrum of Cannabis: A Case of Junctional Bradycardia Triggered by Cannabis Use

Introduction: Cannabis has been increasingly used as a recreational drug. Its cardiovascular effects depend on several factors, including the exact composition, route of administration, dose, and duration of use. Here we report a case of cannabis induced junctional bradycardia in a patient with cardiovascular comorbidities. Case description: A 68-year-old male with history of chronic systolic heart failure, coronary artery disease, diabetes, hypertension and chronic kidney disease was referred to the hospital from outpatient clinic for bradycardia with heart rate 25-35. Patient did not report any symptoms and was hemodynamically stable. He was euvolemic on physical exam. Electrocardiogram (ECG) and telemetry revealed junctional bradycardia with heart rate in 30s and sinus pauses (5-7 seconds). Initial laboratory analysis was unremarkable. He was admitted for further workup of bradycardia. His home medications included metoprolol succinate 25mg daily which was held given bradycardia. Urine drug screen was positive for cannabis. Patient endorsed that he had recently started smoking marijuana to help him with sleep and anxiety. Echocardiogram was unchanged from baseline. He was monitored on telemetry and the heart rate improved to 60-70s in about 24-48 hours without any other intervention. The temporal relationship between cannabis initiation and spontaneous resolution of bradycardia favored a potential causal link for cannabis- induced mechanism for the junctional bradycardia. Patient was resumed on metoprolol prior to discharge and tolerated it well without any bradycardic episodes establishing further that this was not iatrogenic bradycardia. He was counseled to abstain from cannabis use. Conclusion: At low to moderate doses, cannabis can lead to a surge in sympathetic activity causing tachycardia and hypertension, while parasympathetic activity is predominant at higher doses, causing bradycardia and hypotension. Understanding these nuanced effects is crucial for clinicians when evaluating patients especially those with pre-existing cardiovascular conditions. Guidelines should be refined for safer use as the landscape of cannabis legislation evolves

Myocarditis: A Rare Complication of Immune Checkpoint Inhibitor Therapy.

Immune checkpoint inhibitors (ICIs) are a class of immunotherapy agents that are often used in cancer treatment. A rare but life-threatening complication that can be seen is ICI-induced myocarditis. We discuss a case of pembrolizumab-induced myocarditis and the nuances involved in timely diagnosis and treatment. A 64-year-old female with a past medical history significant for metastatic right-sided colorectal adenocarcinoma undergoing immunotherapy with pembrolizumab presented with worsening shortness of breath and was found to be hypoxic. Initial laboratory analysis was remarkable for troponin of 0.35 ng/mL, which later peaked at 6.01 ng/mL. The electrocardiogram showed non-specific ST segment changes in the anteroseptal leads, and a subsequent echocardiogram revealed severely reduced left ventricular systolic function with an ejection fraction of 25%. Coronary angiography showed non-obstructive coronary arteries. As the patient was on pembrolizumab immunotherapy for cancer, there was high suspicion of ICI-induced myocarditis, and the patient was started empirically on steroids. Subsequently, cardiac magnetic resonance imaging was done, which confirmed the diagnosis of myocarditis. Pembrolizumab therapy was discontinued, and she was started on guideline-directed medical therapy for heart failure. While ICIs have transformed cancer therapy, healthcare providers must be vigilant for immune-related adverse events such as myocarditis. Early recognition, prompt management, and close monitoring are crucial for optimizing patient outcomes