Related Experiment Video
Updated: Jul 2, 2026
10:53
Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
Atropine-resistant bradycardia due to hyperkalaemia.
T J Slade1, J Grover, J Benger
1Emergency Department, Bristol Royal Infirmary, Marlborough Street, Bristol, UK. tobyslade@hotmail.com
Emergency Medicine Journal : EMJ
|August 30, 2008
Summary
Symptomatic bradycardia can resist standard treatment. Consider hyperkalemia and administer calcium to stabilize the heart and resolve slow heart rates, especially when atropine fails.
Area of Science:
- Emergency Medicine
- Cardiology
- Internal Medicine
Background:
- Symptomatic sinus bradycardia is a common emergency department presentation.
- Standard treatment involves atropine and cardiac pacing.
Observation:
- Two cases of atropine-resistant symptomatic bradycardia were observed.
- Hyperkalemia was identified as a potential underlying cause.
Findings:
- Hyperkalemia can present as symptomatic bradycardia resistant to atropine.
- Calcium administration stabilizes the myocardium and resolves bradycardia in hyperkalemic patients.
- Blood gas analysis offers rapid serum potassium estimation.
Implications:
- Clinicians should consider hyperkalemia in refractory symptomatic bradycardia.
- Prompt calcium treatment can be life-saving in such cases.
- Utilizing blood gas analysis aids in timely diagnosis and management.
Related Concept Videos
01:24Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...
01:12Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's...
01:14Decreased pulse rate
Bradycardia is a medical condition in which the heart rate is slower than normal. It occurs when the heart's natural pacemaker, the sinus node, generates slower electrical impulses than the standard rhythm. In adults, bradycardia is diagnosed when the pulse rate falls below 60 beats per minute, indicating a deviation from the normal heart rate range.
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with bradycardia...
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with bradycardia...
01:18Dysrhythmias IV: Characteristics of Bradyarrhythmias
Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV...
01:20Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
01:26Heart Failure Drugs: Inotropic Agents
Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...