Cardiac resynchronization therapy and tools to identify responders.

Heart failure is a major epidemic. Many people with heart failure struggle with refractory symptoms despite optimal medical therapy. Those with severe left ventricular dysfunction and ventricular conduction delay are at significant risk from either dying suddenly or dying from progression of their heart failure. Cardiac resynchronization therapy (CRT) improves hemodynamics and symptoms of heart failure and has recently been shown to improve survival. One problem facing the use of CRT is that 30% of patients fail to respond. The dominant theory is that QRS duration (electrical dyssynchrony) does not accurately reflect mechanical dyssynchrony. Echocardiographic tools have recently been developed that enable clinicians to assess the degree of mechanical dyssynchrony in patients being considered for CRT. These tools are able to predict with a significant amount of accuracy whether a patient will respond to CRT. This allows for a more refined approach to evaluating patients for CRT and optimizing the treatment of congestive heart failure.

Evolving strategies for the use of combination therapy in hypertension.

Two thirds of patients with hypertension require more than one drug to achieve goal blood pressure. Rational antihypertensive drug combinations are based on their ability to produce additive blood pressure reduction and reduce the incidence of dose-dependent side effects. Some combinations exhibit side-effect neutralization in which side effects associated with one drug are neutralized by a second agent. Fixed-dose combinations improve adherence by reducing the number of pills and simplifying the treatment regimen. Because volume overload is common, low-dose diuretics are often included in drug combinations. Combinations of diuretics with potassium-sparing diuretics, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and b-blockers are useful in treating large segments of the hypertensive population. Combinations of calcium channel blockers and angiotensin converting enzyme inhibitors are also effective and reduce the incidence of calcium blocker-related edema. Combinations of agents affecting the renin-angiotensin system by different mechanisms are currently the subject of active investigation.

Left anterior descending coronary artery to right ventricular fistula complicating coronary stenting.

Coronary artery perforation is a rare complication of percutaneous transluminal coronary angioplasty (PTCA) and coronary stenting, most commonly creating a communication between the coronary artery lumen and the pericardial space. We report a case where vessel rupture following stent deployment led to the development of a fistula between the left anterior descending coronary artery and the right ventricle.