Role of Cardiac Nerves in the Cardiovascular Response to Cocaine in Conscious Dogs

Shannon, Richard P.; Mathier, Michael A.; Shen, You‐Tang

doi:10.1161/01.cir.103.12.1674

Cited by 7 publications

(4 citation statements)

References 35 publications

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“…This notion is supported by recent study in conscious dogs indicating that baroreceptor denervation leads to augmented pressor and tachycardic response to intravenous cocaine. 27 We therefore speculate that the risk of hypertensive crisis and other catastrophic cardiovascular complications from cocaine is excessive in patients with long-standing hypertension, heart failure, or other pathophysiological conditions accompanied by impaired baroreceptor reflexes.…”

Section: Discussionmentioning

confidence: 92%

Mechanism of the Blood Pressure—Raising Effect of Cocaine in Humans

et al. 2002

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Background-Although the sympathomimetic actions and cardiovascular complications of cocaine are ascribed to inhibition of norepinephrine (NE) reuptake, this hypothesis has not been tested in humans. We asked (a) whether cocaine can inhibit NE reuptake in the human peripheral circulation and (b) whether the NE-mediated peripheral vasoconstriction is the main mechanism mediating blood pressure-raising effect of cocaine. Methods and Results-In 15 healthy cocaine-naive subjects, we measured blood pressure, forearm blood flow, and forearm venous NE concentration during administration of (a) intrabrachial cocaine (0.15 and 15 mg), which produced no systemic neurohormonal effects, and (b) intranasal cocaine (2 mg/kg). Intrabrachial cocaine (0.15 mg) increased venous forearm NE concentration by 82% and vascular resistance by 71% (PϽ0.01). Increasing the intrabrachial cocaine dose by 100-fold to match the venous cocaine level of massive cocaine overdose caused a small additional increase in venous forearm NE concentration without causing significant additional vasoconstriction. Although intranasal cocaine (2 mg/kg) matched the venous cocaine concentrations caused by 0.15 mg of intrabrachial cocaine, venous NE concentration was unchanged as sympathetic nerve activity (SNA) decreased reflexively as the result of an increase in blood pressure. When SNA was restored to baseline by blunting the cocaine-induced rise in blood pressure (baroreflex activation) with nitroprusside, venous NE concentration increased to the same level caused by intrabrachial cocaine. Conclusions-In healthy cocaine-naive individuals, cocaine can inhibit NE reuptake in the human peripheral circulation.However, this mechanism does not contribute importantly to the blood pressure-raising effect of cocaine because activation of baroreceptor reflexes decreases SNA, the neural stimulus for NE release.

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Section: Discussionmentioning

confidence: 92%

Mechanism of the Blood Pressure—Raising Effect of Cocaine in Humans

et al. 2002

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“…Prenatally-cocaine-exposed infants may have structural cardiovascular malformations, cardiopulmonary autonomic dysfunction, and sustained arrhythmias leading to congestive heart failure, cardiorespiratory arrest, and death. 1,2 Cocaine also influences the cardiovascular and autonomic systems through its actions on baroreflex mechanisms 3 and the sympathetic nervous activity.…”

Section: Resultsmentioning

confidence: 99%

Autonomic alterations in cocaine-exposed infants

Mehta

Super

Connuck

et al. 2002

American Heart Journal

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“…It is evident that psychotropic drugs such as cocaine heighten the sympathetic state in animal studies. 31,32 The effect of these drugs and their influence on human autonomic physiology during stun gun discharges is an important aspect that needs urgent evaluation.…”

Section: Knowledge Gapsmentioning

confidence: 99%

Cardiac stimulation with high voltage discharge from stun guns

Nanthakumar¹,

Massé²,

Umapathy³

et al. 2008

Canadian Medical Association Journal

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S tun guns are used to physically incapacitate a person by discharging controlled electrical energy into the body, thereby preventing effective muscular activity. Although the intention is to provide a safe means of subduing an uncooperative person, some studies have suggested that stun guns can stimulate cardiac muscle in addition to skeletal muscle, thus potentially promoting lethal cardiac arrhythmias. In this article, we review the scientific data about the direct effects of stun gun discharges on the heart during shock delivery. We discuss these issues in terms of electrostimulation and correlate them with theoretical and experimental data in the literature. We discuss the principles of cardiac stimulation from internal and external stimulation and examine the evidence for and against cardiac stimulation by stun gun discharges. Stun gun dischargesAn older method of stun guns application, called "drivestun," functioned like a cattle prod, which required direct contact between the electrodes of the source and the target. Stun guns are manufactured by different manufacturers (e.g., Aegis Industries, Stinger Systems, Taser International) and they operate under the general principle of high-voltage discharge with short pulse durations. However, their operation and shock charecteristics vary by manufacturer. For example, a recent model (X26, TASER International) feature 2 barbs attached to long copper wires that are rapidly propelled by compressed nitrogen and adhere to the target's skin or clothes. This stun gun generates an initial 3 microsecond electric pulse, which produces an electrical arc that creates a low-impedance pathway for electricity to reach the body with or without skin contact.1 The initial pulse is followed by longer pulses (100 microseconds) that deliver electrical energy to the target's body, which stimulates his or her nerves and skeletal muscles and results in incapacitation. This pattern is repeated at a frequency of 19 pulses per second. Incapacitation lasts for the duration of the discharge, which is typically 5 seconds but can be 15 seconds or longer if pressure on the trigger is maintained. The TASER X26 battery has the capacity to deliver up to 195 discharges of 5 seconds each, 1 which corresponds to a duration of over 15 minutes. Other devices that have been studied include the M26 (TASER International) and the MK63 Trident (Aegis Industries), which is a stun baton. Each of these devices uses high frequency electrical pulses to incapacitate the target. Method of stunningStunning can be attributed to 1 of 2 methods, which depend on the mode of application. In the "drive stun" method, the overwhelming factor is the creation of pain and hence compliance. The second method, in which electrodes are fired toward the target as projectiles, neuromuscular stimulation occurs over a larger area. In addition to pain, the device incapacitates the target by stimulating his or her motor nerves and muscles as well as sensory neurons. The duration and frequency of the pulses have been optimized to inc...

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Role of Cardiac Nerves in the Cardiovascular Response to Cocaine in Conscious Dogs

Cited by 7 publications

References 35 publications

Mechanism of the Blood Pressure—Raising Effect of Cocaine in Humans

Mechanism of the Blood Pressure—Raising Effect of Cocaine in Humans

Autonomic alterations in cocaine-exposed infants

Cardiac stimulation with high voltage discharge from stun guns

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