Lidocaine is used predominantly for acute treatment of ventricular arrhythmias. It has no efficacy against supraventricular arrhythmias and minimal effects on the autonomic nervous system. It is ideal for acute treatment because it has a rapid onset of action and short half-life (~1 hr in a dog) and is effective and safe.
Full Answer
Can I give my Dog lidocaine for arrhythmia?
Lidocaine, also known as Xylocaine®, is an anesthetic used in dogs and cats for the treatment of abnormal heart rhythms or cardiac arrhythmia. It is also used as a local anesthetic e.g. ... Lidocaine is also an antiarrhythmic agent, one that prevents or treats certain cardiac arrhythmias.
How long does it take for lidocaine to work in dogs?
After the 50 mg. per kilogram dose of lidocaine emesis occurred in five of the six dogs within 105 to 135 minutes while in the sixth dog pronounced lip-licking occurred 180 minutes after this dose. Following 100 mg. per kilogram, emesis occurred in four dogs within 20 to 60 minutes and in one dog 105 minutes afterward.
How does lidocaine treat heart arrhythmias?
Lidocaine is also an antiarrhythmic agent, one that prevents or treats certain cardiac arrhythmias. Lidocaine works by preventing activity of the nerve or heart cell membrane. By blocking the entry of sodium ions the cell is unable to carry messages from cell to cell.
Should I treat my dog’s ventricular arrhythmia?
When deliberating whether to treat a ventricular arrhythmia, one must consider the clinical presentation, associated disease, and natural history. For example, in humans myocardial dysfunction is the major determinant of risk associated with ventricular arrhythmias in man; the extrapolation is most likely true for dogs as well.
Which arrhythmia should not be treated with lidocaine?
Lidocaine is not recommended for prophylactic administration to suppress premature ventricular contractions or prevent ventricular tachycardia or ventricular fibrillation after an acute coronary syndrome.
Why is lidocaine not effective in arrhythmia?
Lidocaine has little effect on atrial arrhythmias as might be predicted from its lack of effect on atrial tissues from normal animals. The drug can, but does not always, cause slight slow- ing of atrial rate in atrial flutter. Also, lidocaine causes no change or decrease in A-V conduction time and A-V refractoriness.
Does lidocaine treat arrhythmias?
LIDOCAINE (Xylocaine) has become one of the most frequently used drugs in the treatment of ventricular arrhythmias, particularly those associated with acute myocardial infarction. It has been shown to terminate ventricular tachycardia, and it has been given to suppress multiple ventricular extrasystoles.
How do you treat ventricular arrhythmias in dogs?
For immediate treatment of ventricular tachycardia in dogs, lidocaine is the drug of choice. For sustained VT, use lidocaine (2-4mg/kg bolus--over a minute) and repeat up to 8mg/kg (total dose over 10 minutes). If successful, perform constant rate infusion (CRI) of lidocaine (40-80mcg/kg/min).
Is amiodarone better than lidocaine?
Amiodarone was more effective than lidocaine in the termination of shock-resistant VT with a cumulative initial VT termination rate of 78% compared with 27% with lidocaine (p <0.05).
Does lidocaine treat AFIB?
Lidocaine has few of the proarrhythmic concerns of most antiarrhythmic drugs and, at high bolus doses, prolongs the atrial refractory period well enough to be effective in converting atrial fibrillation to sinus rhythm. This finding has been previously demonstrated in a dog model.
How does lidocaine affect cardiac function?
Lidocaine administered intravenously has been highly effective in terminating ventricular premature beats and ventricular tachycardia occurring during general surgery, during and after cardiac surgery, following acute myocardial infarction, and in the course of digitalis intoxication.
What does lidocaine do to heart rate?
The administration of lidocaine resulted in a significant overall increase in mean heart rate: for the healthy control group an increase of 5.5 +/- 2.2% (mean +/- SE), for the IMI group an increase of 9.4 +/- 3.5%, and for the AMI group an increase of 8.1 +/- 2.9% (p < 0.01 for all).
Does lidocaine slow down heart rate?
Lidocaine did not affect ventricular conduction time at slow heart rates and had only minimal effects at fast heart rates. Methyl lidocaine increased ventricular conduction time at all heart rates.
How Long Can dogs live with arrhythmia?
For dogs with AF, median survival time (MST) was 142 days (range: 9–478) while dogs without AF lived 234 days (range: 13–879 days).
How common is arrhythmia in dogs?
Arrhythmias are fairly common in dogs, but they're not always a cause for concern. Many dogs with arrhythmias live normal lives without any problems. However, since an arrhythmia may be a red flag for a more serious underlying problem, it is highly recommended to have your dog checked by your vet.
When do you treat ventricular tachycardia in dogs?
Treatment of this arrhythmia should be initiated if the pet's heart rate is greater than 200 beats/minute, and the arrhythmia has been diagnosed by an electrocardiograph. Treatment is also necessary if the pet is showing any clinical signs, such as weakness, syncope (collapse), seizures, or shock.
What is the electrophysiologic effect of class IV antiarrhythmic drugs?
The predominant electrophysiologic effect of class IV antiarrhythmic drugs is blockade of the slow calcium channels in cardiac cells and vascular smooth muscle. The two drugs in this class commonly used in veterinary medicine are diltiazem and amlodipine. The relative affinity of a drug in this class for cardiac versus vascular tissue determines its predominant effect. Amlodipine ( see above) is most active in vascular smooth muscle, where it causes vasodilation and is thus considered to be a vasodilator. Diltiazem is most active in cardiac cells.
What is class II antiarrhythmic?
Class II antiarrhythmic drugs are the β-adrenergic receptor blocking agents. β-Blockers are classified as nonselective (block both β 1 and β 2 receptors) or selective (block predominantly β 1 receptors). As a class, all β-blockers are dose-dependent negative inotropes and chronotropes. Although characterized as class II antiarrhythmic agents, β-adrenergic blockers are used for a variety of indications in veterinary medicine, including control of inappropriate or undesirable sinus tachycardia, treatment of ventricular and supraventricular arrhythmias, management of chronic hypertension in dogs and cats, and palliation of adverse effects of uncontrolled hyperthyroidism in cats and pheochromocytoma in dogs. They are well recognized for their cardioprotective effects in people with heart failure, leading to improved survival. Data and experience supporting this indication in veterinary medicine is lacking in dogs and cats, and the relative risks of initiation of a β-blocker in the face of heart failure should not be ignored. The earliest generation of this class was nonselective, blocking both β 1 and β 2 receptors (eg, propranolol ). Subsequent generations became selective β 1 -receptor blockers in an attempt to limit the adverse effects associated with β 2 -receptor blockade (eg, atenolol ). Third-generation β-blockers (eg, carvedilol) were developed to be more complete adrenergic blockers and are β 1, β 2, and α 1 -receptor blockers. Carvedilol may also have some important antioxidant effects that have contributed to its proven efficacy for treatment of heart failure in people.
What is antiarrhythmics classification?
Antiarrhythmics are typically classified according to their predominant electrophysiologic effect on myocardial cells. However, the electrophysiologic effects of some agents span more than one class, and some have ancillary properties unrelated to their antiarrhythmic effects. However, this classification scheme typically does not aid in selection of an antiarrhythmic for a specific clinical indication (eg, ventricular vs supraventricular arrhythmias). Many antiarrhythmics have never been used with any frequency in veterinary medicine (and are not covered here). In addition, many of these agents (in particular the class I medications) have fallen out of favor for treatment of arrhythmias in people, and as a consequence their availability and costs are becoming problematic.
Does quinidine cause vasodilation?
The atropine -like effects of quinidine may result in increased impulse conduction through the AV node to the ventricles and paradoxical acceleration in ventricular response in animals with atrial fibrillation. Quinidine, particularly in the sulfate form, can cause vasodilation and GI adverse effects (25% of dogs).
Can quinidine be used for dogs?
In dogs, it is used to facilitate synchronized cardioversion of atrial fibrillation. It is not typically used for rate control of chronic atrial fibrillation in dogs or horses, or to treat ventricular arrhythmias. The sulfate preparation of quinidine is absorbed rapidly after administration PO.
Can cats take quinidine?
Quinidine should not be used in cats. Monitoring the ECG and serum quinidine concentration can reduce the likelihood of adverse effects. Procainamide effects are similar to those of quinidine. However, its effects on the autonomic nervous system are significantly weaker (less antivagal effect).
Can quinol cause vasodilation in dogs?
Quinidine, particularly in the sulfate form, can cause vasodilation and GI adverse effects (25% of dogs). In horses, swelling of the nasal mucosa, urticarial wheals, and laminitis are other potential adverse effects.
How long to repeat VT in dogs?
For sustained VT, use lidocaine (2-4mg/kg bolus--over a minute) and repeat up to 8mg/kg (total dose over 10 minutes). If successful, perform constant rate infusion (CRI) of lidocaine (40-80mcg/kg/min).
Is a class I antiarrhythmic better than a class III?
Class I antiarrhythmics are considered more proarrhythmic (humans with asymptomatic VPCs treated with class I antiarrhythmics were more prone to sudden death than the patients who received placebo). Class III antiarrhythmics (Sotalol, Amiodarone, Bretylium) are considered safer, but still with no concrete evidences.
Does mexiletine help with ventricular arrhythmia?
Omega-3 fatty acids have been shown to reduce arrhythmia in animal models and humans, and reduced ventricular arrhythmia in a clinical study with Boxer right ventricular arrhythmogenic cardiomyopathy.
Can ventricular arrhythmias cause death?
Besides that, ventricular arrhythmias may become electrically unstable and degenerate to fatal ventricular fibrillation. Isolated VPCs pose little risk for mortality and have minor effects on blood pressure. However, VPCs may be a risk marker for fatal arrhythmias in some breeds (Dobermann and Boxer).
What is the best medication for ventricular tachycardia in dogs?
Dogs with ventricular tachycardia are the focus of treatment efforts. The most common drugs used today are mexiletine plus atenolol, sotalol, and amiodarone. The later is more commonly used in Europe than in the US in dogs. At Cornell we most commonly use either mexiletine plus atenolol or sotalol.
How fast does a dog's heart beat?
As a general guide, most dogs will have substantial hemodynamic compromise when the heart rate is sustained (greater than 30 seconds) at a rate of greater than 250 beats per minute. In such cases intravenous treatment is ideal. The general rule: If it is really fast, it is really bad.
Why should we be selective about what arrhythmias are treated?
Why should we be selective about what arrhythmias are treated? Because beneficial results may not always occur and adverse effects are possible . Treatment is based upon the assumption that therapy will 1) reduce the risk of death; 2) decrease the frequency of a dangerous arrhythmia; and 3) improve or abolish related clinical signs. 1 Sudden cardiac death can result from ventricular fibrillation (VF), ventricular asystole, or electrical-mechanical dissociation. It was once believed that decreasing the frequency of ventricular extrasystoles would also decrease the risk of sudden death. However, this assumption is not always true. Drugs can have antiarrhythmic effects without antifibrillatory effects and vice versa. If ventricular asystole or electrical-mechanical dissociation is the mechanism of death, then drugs that prevent VF may not affect that outcome.Ventricular premature complexes are not a surrogate for sudden death: Is ventricular tachycardia?
What factors determine the target heart rate for a dog?
The factors to consider in deciding the target heart rate include: 1) size of the dog; 2) underlying disease (lone arrhythmia with normal heart, dilated cardiomyopathy, volume overload with maintained myocardial function); and 3) side effects to medication in an individual patient.
What is a SVT in dogs?
A common type of SVT seen in the dog is one which is not AV node reentrant (positive P wave is present in the caudal leads), does not exactly stop abruptly, frequently has a slight increase in the PR interval or a single P wave just before the arrhythmia breaks, and is usually intermittent and paroxysmal (to a point).
How fast is a dog?
Fast is greater than 160 beats/minute: usually treated. Slow is less than 120 beats/minute: usually not treated. In between is 120-160 beats/minute: may be treated sometimes! These guidelines are subject to change with breed and other factors.
Is mexiletine the same as lidocaine?
The electrophysiologic properties of mexiletine are similar to lidocaine. Therefore, untoward effects are comparable. While VT treated successfully with lidocaine is usually effectively treated with mexiletine, the acute effects of lidocaine do not always predict patient response to mexiletine.
High grade, second-degree atrioventricular (AV) block
Treatment: Atropine or glycopyrrolate is recommended when the patient is hypotensive and bradycardic. ( Image courtesy of J. Gaynor)
Sinus bradycardia with a ventricular escape beat
Treatment: Atropine or glycopyrrolate. The goal is to increase the heart rate as the escape beat is due to the slow sinus rate. (Image courtesty of T. Grubb)