Autonomic responses to tooth clenching and handgrip test

Ventricular tachycardia and acute heart failure induced by atropine in the treatment of bradycardia: A case report and literature review

RATIONALE

Despite various advantages of laparoscopic surgical procedures, artificial pneumoperitoneum might lead to hemodynamic fluctuations including severe bradycardia and cardiac arrest. Atropine is usually proposed to treat intraoperative severe bradycardia ( < 40 beats per minute). However, atropine could induce ventricular arrhythmias, which might be life-threatening in severe case.

PATIENT CONCERNS

Here, we reported a 41-year-old female who was diagnosed with gallbladder polyps and was scheduled for laparoscopic cholecystectomy under general anesthesia.

DIAGNOSES

Bradycardia occurred suddenly during the operation and atropine was injected intravenously. Eventually the patient developed ventricular tachycardia and acute heart failure.

INTERVENTIONS

We organized an urgent consultation and the patient was treated immediately.

OUTCOMES

Fortunately, the patient experienced no complications after timely diagnosis and treatment. After 6 months of follow-up, her New York Heart Association classification was I with no complications.

LESSONS

This case highlighted that the administration of atropine to treat bradycardia may lead to ventricular tachycardia and acute heart failure, and anesthesiologists should remain vigilant to avoid potentially life-threatening consequences.

Prolonged asystole induced by trigeminocardiac reflex accompanied with abnormal heart rate variability during percutaneous balloon compression: a case report

Trigeminocardiac reflex (TCR) can result in bradycardia and even cardiac arrest, and is reversible with elimination of the stimulus. Here, we report the case of a 68-year-old man who experienced cardiac arrest during percutaneous balloon compression for the treatment of trigeminal neuralgia. In this patient, sinus rhythm did not recover after stimulation removal, causing us to successfully perform cardiopulmonary resuscitation (CPR). The patient regained a sinus rhythm and was pretreated with atropine 0.5 mg, allowing the operation to be started again. The operation was completed successfully and the patient experienced no complications. Subsequent heart rate variability (HRV) analysis showed that parasympathetic activity predominated before anesthesia induction and after tracheal intubation. It further elevated during foramen ovale puncture, leading to prolonged asystole. Fortunately, sympathetic activity predominated after atropine was administered, which manifested as an increase in sympathetic activity and a decrease in parasympathetic activity. This could be beneficial for patients with TCR. This case indicates that TCR-related cardiac arrest might not be reversed with stimulus cessation, and atropine played a key role in preventing TCR. Moreover, HRV analysis might be essential for preoperative screening for high-risk patients. We also reviewed the literature for cases of TCR with prolonged asystole.

The contribution of autonomic mechanisms to pain in temporomandibular disorders: A narrative review

BACKGROUND

Temporomandibular disorders (TMD) are diagnosed based on symptom presentation and, like other functional pain disorders, often lack definitive pathology. There is a strong association between elevated stress levels and the severity of TMD-related pain, which suggests that alterations in autonomic tone may contribute to this pain condition.

OBJECTIVES

This narrative review examines the association between altered autonomic function and pain in TMD.

METHODS

Relevant articles were identified by searching PubMed and through the reference list of those studies.

RESULTS

TMD sufferers report an increased incidence of orthostatic hypotension. As in other chronic musculoskeletal pain conditions, TMD is associated with increased sympathetic tone, diminished baroreceptor reflex sensitivity and decreased parasympathetic tone. It remains to be determined whether ongoing pain drives these autonomic changes and/or is exacerbated by them. To examine whether increased sympathetic tone contributes to TMD-related pain through β₂ adrenergic receptor activation, clinical trials with the beta blocker propranolol have been undertaken. Although evidence from small studies suggested propranolol reduced TMD-related pain, a larger clinical trial did not find a significant effect of propranolol treatment. This is consistent with human experimental pain studies that were unable to demonstrate an effect of β₂ adrenergic receptor activation or inhibition on masticatory muscle pain. In preclinical models of temporomandibular joint arthritis, β₂ adrenergic receptor activation appears to contribute to inflammation and nociception, whereas in masticatory muscle, α₁ adrenergic receptor activation has been found to induce mechanical sensitization. Some agents used to treat TMD, such as botulinum neurotoxin A, antidepressants and α₂ adrenergic receptor agonists, may interact with the autonomic nervous system as part of their analgesic mechanism.

CONCLUSION

Even if dysautonomia turns out to be a consequence rather than a causative factor of painful TMD, the study of its role has opened up a greater understanding of the pathogenesis of this condition.