Coronary artery spasm induced by carotid sinus stimulation during neck surgery

Refractory coronary vasospasm complicated by complete atrio-ventricular block during neck surgery: is there an indication for pacing?

Vasospastic angina is a clinical condition characterized by coronary artery spasm in angiographically normal coronary arteries. Vasospastic angina can often lead to ventricular arrhythmias, sudden cardiac death, or life-threatening bradyarrhythmias, such as high-degree atrioventricular block or asystole. We present the unusual case of a woman with depressive syndrome who underwent emergency surgery for hemostasis of a neck lesion that caused hemorrhagic shock after a suicide attempt. During surgery, the electrocardiogram revealed inferior and posterior ST-segment elevation, total atrioventricular block and torsades de pointes; the patient also suffered 4 minutes of cardiac arrest. A temporary pacemaker was placed. Coronary angiography showed right coronary artery vasospasm. Following a second similar episode after tracheostomy, a permanent pacemaker was implanted. The indication for definitive electrostimulation in such a context and the stimulation mechanisms of the carotid sinus underlying vasospasm constitute the interesting points of this clinical case. LEARNING OBJECTIVE: The indication for definitive electrostimulation in a context of recurrent episodes of high-degree atrioventricular block during vasospastic angina and the stimulation mechanisms of the carotid sinus underlying vasospasm constitute the interesting points of this clinical case.

Coronary artery spasm induced by carotid sinus stimulation during arthroscopic shoulder surgery: A case report

RATIONALE

Variant angina is characterized by coronary artery spasm irrespective of the presence of fixed stenotic coronary lesions. Perioperative coronary artery spasm may be induced by the supersensitivity of vascular smooth muscle cells caused by various stimuli, including stimulation of the parasympathetic nervous system.

PATIENT CONCERNS

A 57-year-old male patient was undergoing arthroscopic rotator cuff repair under combined interscalene brachial plexus block and general anesthesia in the lateral decubitus position. While compressing the right shoulder to remove residual irrigation fluid in the shoulder through the surgical site, ventricular fibrillation occurred without ST elevation.

INTERVENTIONS

The patient achieved a return of spontaneous circulation after chest compression, defibrillation, and an epinephrine infusion.

DIAGNOSIS

Postoperative coronary angiography showed no significant stenosis, but it did show that the right coronary artery contracted rapidly and was completely obstructed after an intravascular injection of ergonovine, and that the contracted area returned to its normal size after nitroglycerin was injected into the coronary artery. Based on these observations, the patient was diagnosed with variant angina.

OUTCOMES

The patient was discharged on postoperative day 20 without any sequelae and is currently under follow-up in the Cardiology Department.

LESSONS

Surgeons should be vigilant and take relevant precautions, as compressing the shoulder to remove residual irrigation fluid during arthroscopic shoulder surgery in the lateral decubitus position may stimulate the carotid sinus and cause coronary artery spasm.

Negative chronotropic effects and coronary ischaemic abnormalities following thalidomide therapy

The severe teratogenic side effects of thalidomide led to its well-publicized withdrawal in the 1970s, but as it is cautiously being reintroduced into clinical use, new adverse effects are being described. A 65-year-old male with multiple myeloma received chemotherapy which included cyclophosphamide, thalidomide and dexamethasone. Whilst on this treatment he experienced severe chest pain leading to an acute hospital admission complicated by significant bradycardia with sinus pauses of 7 s, necessitating temporary right ventricular pacing. Despite correction of the bradycardia with temporary pacing, he experienced further episodes of chest pain, during which an ECG (with the pacemaker briefly switched off) showed ST elevation in the inferior leads along with runs of non-sustained ventricular tachycardia. Emergency coronary angiography demonstrated unobstructed coronary arteries. Due to ST elevation in the absence of flow-limiting coronary disease his presentation was presumed to be due to intermittent coronary artery spasm. He was started on sustained-release nifedipine without any beta-blockers and further thalidomide therapy was omitted. On this pharmacological therapy, over a period of 24 months, there were no further recurrences of any cardiac symptoms. To our knowledge there have been no previous reports of coronary artery spasm associated with the use of thalidomide. The precise mechanism remains undefined, with several plausible hypothetical pathways which we discuss. We discuss various mechanisms including autonomic, autocoid and paracrine modes of action that may underlie cardiac side effects of thalidomide. We report coronary spasm in addition to bradycardia as cardiac side effects that cardiologists and oncologists need to be alert to.

A case of coronary artery spasm caused by manipulation of the neck: heart rate variability analysis

A 66-year-old man with no history of ischemic heart disease underwent cervical lymph node dissection. General anesthesia was induced and maintained with remifentanil, along with propofol. With manipulation of the neck and a subcutaneous injection of lidocaine supplemented with adrenaline before the operation, a sudden decrease in blood pressure (BP) and elevation of the ST-T segment appeared on the monitoring electrocardiogram (ECG). Ephedrine, phenylephrine, adrenaline, and nitroglycerin were administered; however, the hypotension was sustained and the ECG abnormalities progressed, along with further elevation of the ST-T segment and a complete atrioventricular block. Following an injection of atropine, the changes in ECG and BP were attenuated. Heart rate variability (HRV) was analyzed using fully recorded monitor variables, and revealed an increase in the high-frequency domain at the time of the cervical manipulation, suggesting simultaneous vagal stimulation and coronary artery spasm. We concluded that the cervical manipulation had increased the vagal tone and we note that HRV analysis was useful to interpret this coronary event.

Cardiac effects of muscarinic receptor antagonists used for voiding dysfunction

Antimuscarinic agents are the main drugs used to treat patients with the overactive bladder (OAB) syndrome, defined as urgency, with or without urgency incontinence, usually with increased daytime frequency and nocturia. Since the treatment is not curative and since OAB is a chronic disease, treatment may be life-long. Antimuscarinics are generally considered to be ‘safe’ drugs, but among the more serious concerns related to their use is the risk of cardiac adverse effects, particularly increases in heart rate (HR) and QT prolongation and induction of polymorphic ventricular tachycardia (torsade de pointes). An elevated resting HR has been linked to overall increased morbidity and mortality, particularly in patients with cardiovascular diseases. QT prolongation and its consequences are not related to blockade of muscarinic receptors, but rather linked to inhibition of the hERG potassium channel in the heart. However, experience with terodiline, an antimuscarinic drug causing torsade de pointes in patients, has placed the whole drug class under scrutiny. The potential of the different antimuscarinic agents to increase HR and/or prolong the QT time has not been extensively explored for all agents in clinical use. Differences between drugs cannot be excluded, but risk assessments based on available evidence are not possible.

Multivessel variant angina after a radical nephrectomy operation

A case of multivessel variant angina after an open radical nephrectomy operation (RNO) is presented. A 52-year-old man was admitted to the coronary care unit with recurrent chest pain and dynamic ST-T wave changes on electrocardiogram early after an RNO. The first diagnosis of the clinical condition was non-ST segment elevation acute coronary syndrome. However, recurrent angina with ST segment elevation occurred after the standard medical therapy, which included beta-blockers. Emergency coronary angiography showed diffuse and multiple narrowing of all the three major coronary arteries during the chest pain, which was relieved by intracoronary nitroglycerine injection. Variant angina was suspected, and beta-blocker therapy was replaced with calcium channel blocker treatment. No angina attacks were observed during the clinical follow-up. Although a direct relationship between the type of surgery and variant angina was not established, coronary vasospasm after an RNO should be kept in mind, especially in the differential diagnosis of a patient with recurrent angina and dynamic ST-T changes on electrocardiogram. Although beta-blocker therapy is a first-line treatment for all acute coronary syndromes, it can be harmful in patients with variant angina and should be stopped immediately after verification of diagnosis.

Coronary artery spasm as a cause of ST elevation and inappropriate implantable cardioverter defibrillator intervention

Coronary artery spasm can cause both brady- and tachyarrhythmia, through induction of AV block (usually linked to coronary spasm of the right coronary artery) or ventricular tachycardia/fibrillation linked to extensive myocardial ischemia. The electrocardiographic aspect of coronary artery spasm is an ST segment elevation. We describe the case of patient implanted with an implantable cardioverter defibrillator (ICD) for unexplained syncope which, during coronary artery spasm, received an inappropriate device firing due to ST segment elevation, leading to a double count of the QRS by the ICD.

Treating patients with overactive bladder syndrome with antimuscarinics: heart rate considerations

In this excellent mini-review, the authors present an extensive and relevant paper on the effect of antimuscarinic agents on the heart. This is without doubt the most detailed and the most reader-friendly paper on this subject, and I am sure that it will help urologists to assist in further educating their patients when prescribing these compounds.

Effects of clonidine and superficial cervical plexus block on hemodynamic stability after carotid endarterectomy

OBJECTIVES

To evaluate the effects of 2 interventions (intravenous clonidine and superficial cervical block) on hemodynamic stability after carotid endarterectomy and to identify variables associated with hemodynamic instability.

DESIGN

Prospective, observational study, sequential enrollment.

SETTING

University hospital.

PARTICIPANTS

Two hundred seventy-five patients undergoing elective carotid endarterectomy under general anesthesia.

INTERVENTIONS

Group NN (n = 50) received no intervention. In group CN (n = 85), 3 mug/kg of clonidine were administered intravenously 30 minutes before the end of the operation. Group CB (n = 140) additionally received a superficial cervical plexus block (SCB) with 20 mL of naropine 0.5% before the induction of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Clonidine alone (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.45-3.76) and clonidine combined with an SCB (OR, 4.99; 95% CI, 3.19-7.82) resulted in a significant increase in hemodynamic stability after CEA (p < 0.001) from 53.3% (NN) to 70.0% (CN) and 83.3% (CB), respectively. The need for rescue medication decreased from 40.0% to 17.6% and 13.6% (p < 0.001). Both interventions significantly reduced the need for postoperative opioid analgesics (p < 0.01). Logistic regression analysis showed preoperative systolic blood pressure values greater than 170 mmHg (OR, 3.23; 95% CI, 1.76-5.93), previous cardiac interventions (OR, 3.3; 95% CI, 1.54-7.11), and the need for rescue medication in the awakening period (OR, 5.8; 95% CI, 2.88-11.52) to be independent risk factors for postoperative hemodynamic instability (p < or = 0.002).

CONCLUSIONS

Intravenous clonidine and superficial cervical block significantly improve cardiovascular stability after carotid endarterectomy. Patients with pre-existing excessive hypertension and previous coronary interventions must be considered a high-risk group.

Intraoperative management: carotid endarterectomies

The management of anesthesia for patients undergoing carotid endarterectomy is challenging and dynamic. Effective management and good outcome requires the anesthesiologist's understanding of cerebral physiology, knowledge of neck anatomy, and understanding of the rapid pathophysiologic changes that occur during carotid artery manipulations. The anesthesiologist must be flexible in the management of patients, who frequently have underlying multiorgan pathology and cardiovascular compromise. Good communication between the anesthetic and surgical teams is needed to avoid irreversible debilitating consequences for the patient.

Coronary vasospasm and the regulation of coronary blood flow

Under physiologic conditions, epicardial arteries contribute minimally to coronary vascular resistance. However, in the presence of endothelial dysfunction, stimuli that normally produce vasodilation may instead cause constriction. Examples include neural release of acetylcholine or norepinephrine, platelet activation and production of serotonin and thrombin, and release of local factors such as bradykinin. This shift from a primary endothelial-mediated vasodilator influence to one of endothelial dysfunction and unchecked vasoconstriction is precisely the milieu in which coronary vasospasm is observed. This condition, which typically occurs during periods of relatively sedentary activity, is associated with focal and transient obstruction of an epicardial arterial segment resulting in characteristic echocardiographic changes and symptoms of myocardial ischemia. This review highlights the current understanding of mechanisms regulating the coronary circulation during health and examines the pathophysiologic changes that occur with coronary spasm. Genetic and other predisposing conditions are addressed, as well as novel therapies based on recent mechanistic insights of the coronary contractile dysfunction associated with coronary spasm.