Case records of the Massachusetts General Hospital. Case 26-2005. A 48-year-old man with sudden loss of consciousness while jogging

Pseudophosphorylation of cardiac myosin regulatory light chain: a promising new tool for treatment of cardiomyopathy

Many genetic mutations in sarcomeric proteins, including the cardiac myosin regulatory light chain (RLC) encoded by the MYL2 gene, have been implicated in familial cardiomyopathies. Yet, the molecular mechanisms by which these mutant proteins regulate cardiac muscle mechanics in health and disease remain poorly understood. Evidence has been accumulating that RLC phosphorylation has an influential role in striated muscle contraction and, in addition to the conventional modulation via Ca²⁺ binding to troponin C, it can regulate cardiac muscle function. In this review, we focus on RLC mutations that have been reported to cause cardiomyopathy phenotypes via compromised RLC phosphorylation and elaborate on pseudo-phosphorylation rescue mechanisms. This new methodology has been discussed as an emerging exploratory tool to understand the role of phosphorylation as well as a genetic modality to prevent/rescue cardiomyopathy phenotypes. Finally, we summarize structural effects post-phosphorylation, a phenomenon that leads to an ordered shift in the myosin S1 and RLC conformational equilibrium between two distinct states.

Managing mass events and competitions with difficult-to-access locations using mobile electrocardiac monitoring

OBJECTIVE

Using mobile wireless technology to monitor ECG in participants of mass events and sports taking place in difficult-to-access location could both prevent and easier detect arrhythmias as well as provide real-time monitoring for any type of injury. We assessed the effectiveness of mobile wireless monitoring technology and IT in detecting possible emergencies during a skyscraper race.

METHODS

We attached specially designed wireless surveillance biopatches on 120 individuals participating to monitor their continuous ECG and location during a skyscraper run-up race at Taipei 101 building, Taiwan. The outcomes of interest were detection of abnormal heartbeats and QRS waves indicative of possible cardiac problems and the exact location of participants during the occurrence of emergencies.

RESULTS

The devices accurately sent over 50 warnings to our monitoring platform when both, danger limits were reached by competitors (<60 or >195 beats per minute) or competitors stopped moving, proving very effective in quickly detecting abnormities and alerting staff of possible emergencies at exact locations.

CONCLUSION

This efficient and inexpensive monitoring method can also prevent arrhythmias in unscreened competitors, the danger of collision among staff and competitors, and preserves oxygen by eliminating additional on-foot monitoring staff. Additionally, it could have multipurpose usage, especially during disasters and accidents occurring in difficult-to-access locations, in military exercises and personal monitoring.