This study asked an interesting question: “Is it safe for a rescuer to continue chest compressions during defibrillation of a rescuee?”

You’d think that with the high voltages involved, and mental images of TV doctors yelling “CLEAR!” before defibrillating, there’s no way it could be safe. Apparently, for a gloved rescuer, even with a “worst-case” accidental connection of electrodes between the two people, the leakage current is well within safety standards.

Between this and the recent change of guidelines for CPR (favoring chest compressions over combined compressions and breathing), the long-time typical methods of resuscitation are suddenly changing a lot.

We do a lot of really cool and scientifically interesting stuff in both our lab and the field as a whole. We have now developed our technology to the point where we can take an MRI scan of a heart and develop a complete model, with accurate fiber directions from diffusion tensor data, in a matter of days if not hours. However, it’s easy to get caught up in the technology and the science and lose sight of clinical endpoints.

This past week, we had the good fortune to be visited by a research scientist from a device company. He pointed out that despite the great sophistication of our knowledge about various CEP minutiae, there remain basic problems with pacing and defibrillation therapies, and with our knowledge of cardiovascular disease in general.

And that brings up a very important point. At times, I’ve felt like we’re patching the symptoms instead of fixing the problem — by researching heart attacks that result primarily from cardiovascular disease, we’re redirecting effort that could be spent on eliminating cardiovascular disease in the first place. For example, it seems vegetarians may have around a 20% smaller risk of death from ischemic heart disease than non-vegetarians. Occasional meat eaters fall between meat-eaters and vegetarians. (Please note that I don’t think that one study is conclusive — I haven’t done a thorough literature search.) To keep things honest, this study suggests that in British vegetarians, differences in mortality may be due to other lifestyle factors.

Here are some other articles on the subject, with their conclusions:

• Dietary determinants of ischaemic heart disease in health conscious individuals. – Conclusion: In these relatively health conscious individuals the deleterious effects of saturated animal fat and dietary cholesterol appear to be more important in the aetiology of IHD than the protective effect of dietary fibre. Reduced intakes of saturated animal fat and cholesterol may explain the lower rates of IHD among vegetarians compared with meat eaters. Increasing BMI within the normal range is associated with increased risk of IHD. The results have important public health implications.
• Dietary habits and mortality in 11,000 vegetarians and health conscious people: results of a 17 year follow up. – Conclusion: In this cohort of health conscious individuals, daily consumption of fresh fruit is associated with a reduced mortality from ischaemic heart disease, cerebrovascular disease, and all causes combined.
• Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. – Conclusion: Further categorization of diets showed that, in comparison with regular meat eaters, mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lactoovovegetarians, and 26% lower in vegans.
• Lifestyle determinants and mortality in German vegetarians and health-conscious persons: results of a 21-year follow-up. – Conclusion: Both vegetarians and nonvegetarian health-conscious persons in this study have reduced mortality compared with the general population. Within the study, low prevalence of smoking and moderate or high level of physical activity but not strictly vegetarian diet was associated with reduced overall mortality.
• Mortality in British vegetarians: review and preliminary results from EPIC-Oxford. – Conclusion: The mortality of both the vegetarians and the nonvegetarians in these studies is low compared with national rates. Within the studies, mortality for major causes of death was not significantly different between vegetarians and nonvegetarians, but the nonsignificant reduction in mortality from ischemic heart disease among vegetarians was compatible with the significant reduction previously reported in a pooled analysis of mortality in Western vegetarians.
• Long-term low-calorie low-protein vegan diet and endurance exercise are associated with low cardiometabolic risk. – Conclusion: Long-term consumption of a low-calorie low-protein vegan diet or regular endurance exercise training is associated with low cardiometabolic risk. Moreover, our data suggest that specific components of a low-calorie low-protein vegan diet provide additional beneficial effects on blood pressure.

After reading over these abstracts, my suspicions and some things I have heard have been confirmed: It’s really hard to get conclusive evidence out of human studies.

Even if everyone on the planet simultaneously switched to the optimum diet for minimizing heart disease, whatever that is, there would still be a need for treatment of ischemic heart disease in the form of defibrillator devices for the next several decades, as in many people the damage is already done. With that in mind, it is important that we as a research community focus our work on developing helpful therapies rather than keeping to our ivory towers.