Slow-infusion of calcium channel blockers in the emergency management of supraventricular tachycardia

Digoxin for the Management of Unstable Paroxysmal Supraventricular Tachycardia in a Patient Who Refused Electrical Cardioversion in a Rural Hospital

Background

The most frequent atrioventricular tachycardia in the emergency room is atrioventricular nodal reentrant tachycardia (AVNRT). The first treatment option for ending stable narrow QRS complex SVTs is vagal maneuvers and adenosine. When adenosine or vagal maneuvers fail to change a patient's rhythm to normal sinus rhythm, long-acting AV nodal-blocking medications, including nondihydropyridine calcium channel blockers (verapamil and diltiazem), flecainide, or beta-blockers, are employed. Electricity (synchronized cardioversion) is the preferred form of treatment for unstable patients. Case Presentation. A 40-year-old male patient presented to the Emergency Department of Dubti General Hospital, the Afar regional state in Ethiopia, with a complaint of shortness of breath, palpitation, extreme fatigue, and chest pain of a day's duration. His blood pressure was 80/50 mmHg, he had cold extremities and a weak radial pulse, and his apical heart rate was fast, making it difficult to count. His electrocardiogram (ECG) showed paroxysmal supraventricular tachycardia (PSVT) with a heart rate of 200. He was a candidate for electrical cardioversion due to unstable PSVT, but he and his family members refused to give consent. Even though he is not indicated for pharmacologic therapy, none of the commonly used drugs were available at the hospital. We managed him with digoxin, and the outcome was positive.

Conclusion

Even though we could not find a clear recommendation regarding the use of digoxin for patients with unstable PSVT (AVNRT), by taking into consideration its negative chronotropic effect and its action to suppress the AV nodal conduction velocity, it may reduce the heart rate, and it can be used as an alternative in such difficult scenarios and a resource-limited setting. But this should be further investigated.

Singapore Advanced Cardiac Life Support Guidelines 2021

Advanced cardiac life support (ACLS) emphasises the use of advanced airway management and ventilation, circulatory support and the appropriate use of drugs in resuscitation, as well as the identification of reversible causes of cardiac arrest. Extracorporeal cardiopulmonary resuscitation and organ donation, as well as special circumstances including drowning, pulmonary embolism and pregnancy are addressed. Resuscitation does not end with ACLS but must continue in post-resuscitation care. ACLS also covers the recognition and management of unstable pre-arrest tachy- and bradydysrhythmias that may deteriorate further.

Management of tachyarrhythmias in pregnancy - A review

The most common arrhythmias detected during pregnancy include sinus tachycardia, sinus bradycardia, and sinus arrhythmia, identified in 0.1% of pregnancies. Isolated premature atrial or ventricular arrhythmias are observed in 0.03% of pregnancies. Arrhythmias may become more frequent during pregnancy or may manifest for the first time.

Advanced Cardiac Life Support: 2016 Singapore Guidelines

The main areas of emphasis in the Advanced Cardiac Life Support (ACLS) guidelines are: early recognition of cardiac arrest and call for help; good-quality chest compressions; early defibrillation when applicable; early administration of drugs; appropriate airway management ensuring normoventilation; and delivery of appropriate post-resuscitation care to enhance survival. Of note, it is important to monitor the quality of the various care procedures. The resuscitation team needs to reduce unnecessary interruptions to chest compressions in order to maintain adequate coronary perfusion pressure during the ACLS drill. In addition, the team needs to continually look out for reversible causes of the cardiac arrest.

Rhythm disturbances

Patients with cardiac rhythm disturbances may present in a variety of conditions. Patients may be unstable, requiring immediate interventions, or stable, allowing for a more deliberate approach. Rapid assessment of patient stability, underlying rhythm, and determination of appropriate interventions guides timely therapy. This article discusses the differential diagnosis and treatment of adult patients presenting with primary bradyarrhythmias and tachyarrhythmias, with the exception of atrial fibrillation and atrial flutter, covered elsewhere in this issue. A concise approach to diagnosis and determination of appropriate therapy is presented.

Chemical cardioversion of supraventricular tachycardia with calcium gluconate

BACKGROUND

Approximately 0.05% of Emergency Department visits in the United States are related to supraventricular tachycardia (SVT). The majority of patients convert with an atrioventricular nodal blocking medication.

CASE REPORT

We report a case of SVT that converted after administration of calcium gluconate after failing conversion with adenosine.

CONCLUSION

Conversion to normal sinus rhythm resulted after administration of i.v. calcium in our patient. Additional investigations would be helpful in determining the causal vs. temporal association of conversion of SVT with calcium administration.

Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.

Diltiazem facilitates inactivation of single L-type calcium channels in guinea pig ventricular myocytes

Diltiazem is a benzothiazepine Ca2+ channel blocker used clinically for its antihypertensive and antiarrhythmic effects. We studied the mechanism of diltiazem blockade by recording L-type Ca2+ channel currents from cell-attached patches in isolated guinea pig ventricular myocytes using Ba2+ as the charge carrier. With diltiazem (200 microM) in the superfusate, multichannel currents showed a use-dependent decline in amplitude reflecting reductions in the numbers of superpositions of channel openings. Analysis of single-channel currents revealed that both open and closed times were little affected by diltiazem (50 and 100 microM). However, the rate of decay of the averaged current during 150-ms depolarization steps was significantly accelerated and the open state probability in current containing-sweeps was significantly decreased by diltiazem, suggesting that the drug accelerates transition from the activated state to the inactivated state. The effect of diltiazem on the slow gating process was studied by repetitively applying 500-1000 step pulses at selected holding potentials. Decreased channel availability by diltiazem was reflected by the increasing number of blank sweeps per run at depolarized holding potentials. These results suggest that diltiazem reduces Ca2+ influx by accelerating inactivation during action potentials, and that the use-dependent blockade is due to increases in the number of channels in a sustained closed state.