the Natural Condition

The situation: you are by yourself, and you begin to have severe chest pain, followed by acute vertigo. You are having a heart attack, and moments later you feel like you are about to faint. With a few seconds left before you lose consciousness, what do you do?

In truth, you should dial 911 on your cell phone. But after that… cough, deeply and forecefully, about once every 1 to 3 seconds. Long derailed as a hype product of the devious “world-wide web,” improvised ‘cough CPR’ may actually have some merit, according to some cardiovascular researchers. The idea of coughing to sustain arterial pressure and to induce blood flow first appeared in the Journal of the American Medical Association in 1976¹. Therein, the authors purported that coughing during ventricular fibrillation not only kept several patients conscious for up to 39 seconds after the onset of VF, but that coughing maintained arterial pressure at almost 140mmHg, compared to only 60mmHg for traditional chest compressions. That is, they indicated that ‘cough-CPR’ could have advantages over normal CPR.

And while the American Heart Association, formally and adamantly, does not endorse the maneuver², scientists continue to demonstrate that coughing during a heart attack can actually help blood circulate. The picture below shows the EKG of cardiac rhythms overlaid with femoral artery pressure:

^{A: normal sinus, B: rapid coughing, C: slower coughing, D: no intervention.
Image courtesy of Circulation.}

The diagram clearly shows that coughing can most definitely maintain arterial pressure. Indeed, the authors of the diagrammed study believe that:

(1) Arterial pressures were superior to any produced by conventional CPR and clearly maintained perfusion.
(2) Coughing was spontaneous and could occur outside of “a monitored setting.” [AHA issue]
(3) Cough CPR can be effectively taught to high-risk patients and could save lives.³

However, other scientists speculate that, although there is a spike in arterial pressure caused by the increased thoracic pressure of the cough, the blood does not actually flow because each cough is followed by a large inhalation — very low pressure⁴. It seems to me that forcefully expelling air once a second — otherwise known as hyperventilation — might, itself, cause you to faint. But if you are caught all alone with a severe heart attack, coughing could prolong consciousness, albeit temporarily, until more decisive help arrives. It is probably worth a shot, considering the alternatives…

Which brings us to the next point: when to have a heart attack. An article published in this week’s JAMA found that survival of in-hospital cardiac arrest is statistically better during the daytime than at night, and during the weekdays rather than on weekends, even when controlled for “patient, event, and hospital characteristics.”⁵ The diagram below outlines the differences in survival:

^{Image courtesy of JAMA.}

Interestingly, while nighttime survival rates from in-hospital cardiac arrest were always about 5% worse than daytime incidents (~14% and ~21%, respectively), nighttime ones experienced no drop in survival on the weekends as the daytime ones did (~17% on weekends, down from ~21% on weekdays). They concluded that there is a “need to focus on night and weekend hospitalwide resuscitation system processes of care.”⁵

In conclusion, if you find yourself experiencing cardiac arrest, you should cough, and hope that the sun is shining on you.

Footnotes:
(1) Cough-induced cardiac compression:self-administered form of cardiopulmonary resuscitation. JAMA. 1976..
(2) Cough CPR. American Heart Association.
(3) Cough Cardiopulmonary Resuscitation Revisited. Ciruculation. 2006.
(4) Letter to the editor regarding “Cough Cardiopulmonary Resuscitation Revisited.”
(5) Survival From In-Hospital Cardiac Arrest During Nights and Weekends. JAMA. 2008. [full text - limited access]