Effect of reperfusion strategy on QT dispersion in patients with acute myocardial infarction: Impact on in-hospital arrhythmia

BACKGROUND

Myocardial ischemia and ST-elevation myocardial infarction (STEMI) increase QT dispersion (QTD) and corrected QT dispersion (QTcD), and are also associated with ventricular arrhythmia.

AIM

To evaluate the effects of reperfusion strategy [primary percutaneous coronary intervention (PPCI) or fibrinolytic therapy] on QTD and QTcD in STEMI patients and assess the impact of the chosen strategy on the occurrence of in-hospital arrhythmia.

METHODS

This prospective, observational, multicenter study included 240 patients admitted with STEMI who were treated with either PPCI (group I) or fibrinolytic therapy (group II). QTD and QTcD were measured on admission and 24 hr after reperfusion, and patients were observed to detect in-hospital arrhythmia.

RESULTS

There were significant reductions in QTD and QTcD from admission to 24 hr in both group I and group II patients. QTD and QTcD were found to be shorter in group I patients at 24 hr than those in group II (53 ± 19 msec vs 60 ± 18 msec, P = 0.005 and 60 ± 21 msec vs 69+22 msec, P = 0.003, respectively). The occurrence of in-hospital arrhythmia was significantly more frequent in group II than in group I (25 patients, 20.8% vs 8 patients, 6.7%, P = 0.001). Furthermore, QTD and QTcD were higher in patients with in-hospital arrhythmia than those without (P = 0.001 and P = 0.02, respectively).

CONCLUSION

In STEMI patients, PPCI and fibrinolytic therapy effectively reduced QTD and QTcD, with a higher observed reduction using PPCI. PPCI was associated with a lower incidence of in-hospital arrhythmia than fibrinolytic therapy. In addition, QTD and QTcD were shorter in patients not experiencing in-hospital arrhythmia than those with arrhythmia.

Best Vascular Access in the Elderly: Time for Innovation?

BACKGROUND

Conflicting data continue to surround the optimal dialysis access for the elderly. Many propose that catheters are the best option for this population; others emphasize the creation of an arteriovenous fistula.

SUMMARY

While an arteriovenous access is the best available access, it has a high early failure rate, particularly in the elderly. However, significant differences exist in forearm (men ≥65 years ~70%; women ≥65 years ~80%) versus upper arm (men ≥65 years ~40%; women ≥65 years ~38%) fistula failure rates in the elderly, with upper arm having much lower failure rates. Two percutaneous innovative techniques that successfully establish fistulas at the upper arm using proximal radial/ulnar -artery as the inflow have been recently introduced. These procedures have been successfully performed in the elderly. Importantly, these techniques bypass the open surgical exploration and as such avoid the surgical manipulation of the juxta-anastomotic region (a common cause for the development of juxta-anastomotic stenosis and early fistula failure). Key Message: This article discusses the arteriovenous fistula creation in the elderly, highlights the factors necessary for successful fistula creation, and describes the 2 innovative techniques that can be used to provide a robust platform for successful fistula creation in this population.

Management of spasticity after spinal cord injury: current techniques and future directions

Spasticity, resulting in involuntary and sustained contractions of muscles, may evolve in patients with stroke, cerebral palsy, multiple sclerosis, brain injury, and spinal cord injury (SCI). The authors critically review the neural mechanisms that may contribute to spasticity after SCI and assess their likely degree of involvement and relative significance to its pathophysiology. Experimental data from patients and animal models of spasticity as well as computer simulations are evaluated. The current clinical methods used for the management of spasticity and the pharmacological actions of drugs are discussed in relation to their effects on spinal mechanisms. Critical assessment of experimental findings indicates that increased excitability of both motoneurons and interneurons plays a crucial role in pathophysiology of spasticity. New interventions, including forms of spinal electrical stimulation to suppress increased neuronal excitability, may reduce the severity of spasticity and its complications.