What is the clinical evidence from this study?

Study design: Observational. Population: Healthy (n=12). Intervention: Breath-hold diving at 5-m depth vs. Out of water (basal) and surface immersion. Primary outcome: Cardiac output (p=<0.001).

May 9, 2008Journal of Applied PhysiologyOpen Access

Breath-hold diving at 5-m depth significantly reduced cardiac output to 3.8 L/min compared to 6.3 L/min at baseline, indicating a constrictive effect on the heart from increased environmental pressure.

Q: What are the key findings of this study?

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Why the study?

Does breath-hold diving at 5-m depth alter cardiac output and left ventricular diastolic function in healthy humans?

Population

12 healthy male subjects, experienced active breath-hold divers, with no history of cardiovascular or…

Comparison

Breath-hold diving at 5-m depth and other… vs Out of water condition and comparisons between…

Design

Cohort, Analysis was made offline by an expert in Doppler-echocardiography…

Key result

Breath-hold diving at 5-m depth significantly reduced cardiac output to 3.8 L/min compared to 6.3 L/min at baseline, indicating a constrictive effect on the heart from increased environmental pressure.

Authors

CMC Marabotti ASAlessandro Scalzini DCDanilo Cialoni

Discussion

Member takes

Overview

May warrant caution in breath-hold divers with cardiac conditions; leaves open effects at greater depths or in disease.

Study Design

Type

Observational (n=12)

Multicenter

Structured PICO

Does breath-hold diving at 5-m depth alter cardiac output and left ventricular diastolic function in healthy humans?

Population

12 healthy male experienced breath-hold divers underwent underwater echocardiography to evaluate cardiovascular responses to immersion and diving.

Exposure

Breath-hold diving at 5-m depth (condition D) and other immersion conditions (head-out immersion, full immersion at surface breathing, full immersion at surface breath-holding).

Comparator

Out of water (basal) condition and comparisons between different immersion states.

Outcome

Changes in heart rate, left ventricular volumes, stroke volume, cardiac output, and left ventricular diastolic function indexes (E peak, A peak, E/A, DTE) measured by underwater two-dimensional Doppler echocardiography.surrogate

Main Result

Absolute Event Rate: 3.8% vs 6.3%

p-value: p=<0.001

Breath-hold diving at 5-m depth induces a significant reduction in cardiac output and left ventricular volumes, likely due to increased environmental pressure causing a constrictive effect on the heart.

Limitations

Small sample size
Only male subjects were included
The sequence of echocardiographic studies could not be randomized due to technical difficulties
Echocardiography may be inefficient in accurately detecting small changes in right ventricle dimensions
Absence of female subjects
Time necessary for handling equipment prevented consecutive testing of all conditions in each subject
Only apical four-chamber view and transmitral flow recorded during diving to minimize duration
Intrinsic inefficiency of echocardiography in accurately detecting small changes in right ventricle dimensions

Cite This Study

Marabotti et al. (2008) conducted an observational in Healthy (n=12). Breath-hold diving at 5-m depth vs. Out of water (basal) and surface immersion was evaluated on Cardiac output (p=<0.001). Breath-hold diving at 5-m depth significantly reduced cardiac output to 3.8 L/min compared to 6.3 L/min at baseline, indicating a constrictive effect on the heart from increased environmental pressure.

synapsesocial.com/papers/6a75ddc54555d8f90b706f97 https://doi.org/10.1152/japplphysiol.00126.2008

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May 9, 2008Journal of Applied PhysiologyOpen Access

Breath-hold diving at 5-m depth significantly reduced cardiac output to 3.8 L/min compared to 6.3 L/min at baseline, indicating a constrictive effect on the heart from increased environmental pressure.

View Full Paper

Ask AI

Bookmark

Why the study?

Does breath-hold diving at 5-m depth alter cardiac output and left ventricular diastolic function in healthy humans?

Population

12 healthy male subjects, experienced active breath-hold divers, with no history of cardiovascular or…

Comparison

Breath-hold diving at 5-m depth and other… vs Out of water condition and comparisons between…

Design

Cohort, Analysis was made offline by an expert in Doppler-echocardiography…

Key result

Authors

CMC Marabotti ASAlessandro Scalzini DCDanilo Cialoni

Discussion

Member takes

Overview

May warrant caution in breath-hold divers with cardiac conditions; leaves open effects at greater depths or in disease.

Study Design

Type

Observational (n=12)

Multicenter

Structured PICO

Does breath-hold diving at 5-m depth alter cardiac output and left ventricular diastolic function in healthy humans?

Population

12 healthy male experienced breath-hold divers underwent underwater echocardiography to evaluate cardiovascular responses to immersion and diving.

Exposure

Breath-hold diving at 5-m depth (condition D) and other immersion conditions (head-out immersion, full immersion at surface breathing, full immersion at surface breath-holding).

Comparator

Out of water (basal) condition and comparisons between different immersion states.

Outcome

Main Result

Absolute Event Rate: 3.8% vs 6.3%

p-value: p=<0.001

Limitations

Small sample size
Only male subjects were included
The sequence of echocardiographic studies could not be randomized due to technical difficulties
Echocardiography may be inefficient in accurately detecting small changes in right ventricle dimensions
Absence of female subjects
Time necessary for handling equipment prevented consecutive testing of all conditions in each subject
Only apical four-chamber view and transmitral flow recorded during diving to minimize duration
Intrinsic inefficiency of echocardiography in accurately detecting small changes in right ventricle dimensions

Cite This Study

synapsesocial.com/papers/6a75ddc54555d8f90b706f97 https://doi.org/10.1152/japplphysiol.00126.2008

Also Consider

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