Studies related to Heart Rate and Marijuana

Acute Effects Of Marihuana Smoking On Maximal Exercise Performance

Effect Increase
Trial Design Cohort
Trial Length 1-7 Days
Number of Subjects 12
Gender Both Genders
Age Range 18-29
Body Types Average
Notes for this study:
In healthy nonsmoking adults who inhaled marijuana (7mg/kg bodyweight of a product that was 1.7% THC) and then cycled until failure, the marijuana group cycled for 15.1+/-3.3m relative to control's 16.1+/-4.0 (6.2% reduction) despite VO2 max not being affected.

This study did not utilize a blinding procedure, instead having a no smoking control, and a 26% increase in heart rate was noted before exercise (this increase in heart rate persisted up until 80% of maximum effort, but at 90-100% maximum effort during exercise both groups were similar).

Blood pressure during exercise was lower with marijuana relative to control, and FEV1 was increased with marijuana.

Cardiovascular Effects Of Prolonged Delta-9-tetrahydrocannabinol Ingestion

Effect Decrease
Trial Design Cohort
Trial Length 1-2 Weeks
Number of Subjects 14
Gender Male
Age Range 18-29, 30-44
Notes for this study:
Chronic administration of THC ingestion in hospitalized volunteers was associated with a reduction in heart rate after the initial increase observed with THC, and a reduction in blood pressure was also noted.

Orthostatic hypotension was also noted acutely, but subjects became tolerant to this effect of THC even when the peripheral hypotension was still present. Tolerance was associated with an increase in total body water and weight.

Postural Syncope After Marijuana: A Transcranial Doppler Study Of The Hemodynamics

Effect Decrease
Trial Design Double blind
Trial Length 24 hours
Number of Subjects 29
Gender Both Genders
Age Range 18-29, 30-44
Notes for this study:
Administration of marijuana (as inhalant), relative to placebo, was associated with some subjects experiencing orthostatic symptoms (28% of the study) and in these persons symptoms peaked immediately after inhalation and was associated with a drop in cerebral blood flow.

Opioid Antagonism Enhances Marijuana's Effects In Heavy Marijuana Smokers

Effect Increase
Trial Design Double blind
Trial Length 1-7 Days
Number of Subjects 29
Gender Both Genders
Age Range 18-29
Notes for this study:
In a study assessing the interactions of naltrexone and marijuana, when comparing the marijuana only group against the double placebo group in heavy smokers, marijuana alone (800mg of a 3.27% THC cigarette) was insufficient to impair psychomotor performance, short term memory, or attention on computerized testing (DRT, DAT, DSST).

Peripheral effects of marijuana (heart rate) also appeared to be enhanced alongside the enhanced neurological high in these heavy users.

Tolerance To Effects Of High-dose Oral δ9-tetrahydrocannabinol And Plasma Cannabinoid Concentrations In Male Daily Cannabis Smokers

Effect Increase
Trial Design Cohort
Trial Length 1-7 Days
Number of Subjects 13
Gender Male
Age Range 13-17, 18-29, 30-44
Body Types Average
Notes for this study:
Oral supplementation of THC around the block (dosing every 3.5-6 hours) of increasing doses in order to induce tolerance was met with an increase in heart rate (9-14BPM) and decrease in diastolic blood pressure (9-10mmHg) which did not dissipate during tolerance. Systolic BP was unaffected.

http://www.nejm.org/doi/full/10.1056/NEJM197308162890702
Effect Increase
Trial Design doubleblind
Trial Length 24weeks
Number of Subjects 32
Gender m
Notes for this study:
In experienced male marijuana smokers (at least 3 sessions a week for six months) who refrained from cannabis for two weeks prior to being included in a metabolic ward study (36 days) and smoked 7mg/kg (1% or 2% THC) marijuana daily was able to significantly increase airway conductance and heart rate within the hour after smoking with effects being nonsignificantly dose-dependent. Oral THC also had these effects, but rather than being effective within 60 minutes they required 120-360 minutes. Placebo inhalation and cigarettes both acutely impaired lung function.

The Effects Of Smoking Marihuana On Physical Performance

Effect Increase
Trial Design Double blind
Trial Length 24 hours
Number of Subjects 20
Gender Male
Age Range 18-29
Body Types Average
Notes for this study:
In adults who reported marijuana usage, inhalation of marijuana (20-25 tokes to finish off 1.4g of marijuana, conferring 18.2mg THC) before exercise failed to influence power output as assessed by a grip strength test but was successful in reducing endurance performance on a cycling test by 25% when performance was being held at 170 BPM (heart rate).

At rest, diastolic blood pressure (by 15mmHg) and heart rate (from 73.7BPM to 105.8BPM) were increased with marijuana, with an apparent increase in systolic blood pressure as well. Blood flow appeared to be unaffected.
Funding issues for this study:
Funding was from the Medical Research Council of Ottawa (Canada)

Lack Of Analgesia By Oral Standardized Cannabis Extract On Acute Inflammatory Pain And Hyperalgesia In Volunteers

Effect Increase
Trial Design Double blind
Trial Length 24 hours
Number of Subjects 18
Gender Female
Age Range 18-29
Body Types Average
Notes for this study:
In 18 otherwise healthy female volunteers who ingested 20mg THC with a meal and then were tested on various pain tests, there was a failure for THC to reduce pain in a capsaicin intradermal test (2.5 hours after ingestion) despite this being in the time range of peak plasma THC concentrations (2-4 hours). The pain associated with a sunburn test was also not affected any differently than placebo.

This dose of marijuana did not affect blood pressure (despite an increase in heart rate) and had psychoactive effects.

Regional Cerebral Blood Flow After Marijuana Smoking

Effect Increase
Trial Design Double blind
Trial Length 24 hours
Number of Subjects 20
Gender Male
Age Range 18-29
Body Types Average
Notes for this study:
Acute inhalation of two doses of marijuana (1.75% THC cigarette or 3.55%) appeared to increase global cerebral blood flow in both hemispheres when tested after 30-60 minutes, but not after 120 minutes. These changes were associated with an increase in tension/anger, intoxication, but no significant differences in blood pressure noted.

Placebo cigarettes were used in this study, and while the study was acute in nature it was conducted in persons with a history of marijuana usage who did not consume any two weeks prior to the study.

Effect Of Marihuana On Intraocular And Blood Pressure In Glaucoma

Effect Increase
Trial Design Cohort
Trial Length 24 hours
Number of Subjects 18
Gender Both Genders
Notes for this study:
In subjects with glaucoma (heterogenous origin) inhaling marijuana experienced a decrease in peripheral and intraocular blood pressure 60-90 minutes after inhaling, coinciding with the other expected effects of marijuana including an increase in heart rate and psychoactive effects.