Targeting tachycardia: diagnostic tips and tools.

Many narrow QRS complex tachycardias are benign, but some require rapid intervention. The review, EKG strips, and algorithm you'll find here will help you get to the source of the problem without delay.

Clinical utility of aVR-The neglected electrocardiographic lead.

BACKGROUND: Several studies suggest that electrocardiographers tend to neglect lead aVR during the reading of electrocardiograms (ECGs). Our objective was to provide a systematic review of the most important diagnostic and prognostic uses of lead aVR. METHODS: We performed a thorough review of the literature about the lead aVR using PubMed, MEDLINE and the archives of the University at Buffalo libraries. RESULTS: We found that lead aVR may provide important additional information in the diagnosis of coronary artery disease. It may provide a clue to the location of a lesion as well as the possibility of three vessel disease during an acute coronary syndrome. Lead aVR was found useful in the locus of arrhythmias and in differentiation of narrow and wide QRS complex tachycardias. It provides useful prognostic information for patients with the Brugada syndrome and tricyclic antidepressant toxicity. Lead aVR provides alternative criteria for the electrocardiographic diagnosis of left ventricular hypertrophy and left anterior fascicular block. CONCLUSION: Lead aVR provides very important additional diagnostic and prognostic information in multiple cardiac conditions and can be used either alone or in conjunction with other electrocardiographic leads.

The role of revascularization versus medical therapy in patients with type 2 diabetes mellitus and coronary artery disease.

Patients with type 2 diabetes mellitus (T2DM) are at increased risk for cardiovascular clinical events, adverse nonfatal outcomes, and death. There has been considerable improvement in the medical management of patients with T2DM in an attempt to alter the metabolic cascade that is triggered by insulin resistance. Recent trials have demonstrated that medical management of patients with diabetes mellitus and stable coronary artery disease (CAD) is equivalent to revascularization in terms of morality benefit and rates of major adverse cardiovascular events, particularly in patients who do not have extensive CAD. Nonetheless, in those diabetic patients with additional high-risk features including left main disease, reduced left ventricular ejection fraction (LVEF), severe ischemia, or acute coronary syndrome, revascularization remains the best treatment option. Although the evidence still supports coronary artery bypass grafting (CABG) as the standard of care for revascularization of diabetic patients with multivessel CAD and/or reduced LVEF, percutaneous coronary intervention (PCI) with drug-eluting stents (DES) has resulted in at least partial closure of the gap in benefit between surgery and catheter-based intervention. Ongoing trials of diabetic patients with CAD randomized to PCI or CABG will help further elucidate the role of PCI with DES as a potential revascularization option for this patient population.

Management of acute ST-elevation myocardial infarction: Reperfusion options.

Primary percutaneous coronary intervention and thrombolysis remain therapies of choice for patients presenting with ST-segment elevation myocardial infarction (STEMI). Clinical outcome in the management of acute STEMI is dependent on myocardial reperfusion time and reperfusion strategies. Optimisation of these strategies should take into consideration logistical limitations of the local medical systems and the various patient profiles. We review the reperfusion strategies and its history in Singapore, comparing its clinical application with that in some developed Western countries.

Reversible electrocardiogram changes and cardiomyopathy secondary to baclofen withdrawal syndrome.

Baclofen withdrawal syndrome is a rare and potentially life-threatening condition manifesting with autonomic dysreflexia, high fevers, spasticity, seizures, and multiorgan failure. Reversible cardiomyopathy due to this condition is extremely rare. A high level of suspicion is needed to recognize this condition and start an early intervention to improve patient outcome. Electrocardiographic ST-segment elevation in lead aVR was previously described in association with left main, left anterior descending, and triple-vessel coronary artery disease as well as Takotsubo cardiomyopathy. In this article we present a rare case of reversible cardiomyopathy due to baclofen withdrawal syndrome associated with diffuse ST-segment depressions and ST-segment elevation in lead aVR.

Abnormal myocardial perfusion in a patient with left ventricular non-compaction.

Isolated left ventricular non-compaction is a rare congenital cardiomyopathy. Patients frequently present with signs of heart failure and dyspnea on exertion. Myocardial perfusion tests using single photon emission computed tomography are frequently used for evaluation of ischemia. In this case report we present myocardial perfusion images of isolated left ventricular non-compaction from a patient who was referred to our center for evaluation of dyspnea on exertion.

50th Anniversary of the first successful permanent pacemaker implantation in the United States: historical review and future directions.

June 2010 marks the 50th anniversary of the first successful human cardiac pacemaker implantation in the United States. On June 6, 1960, in Buffalo, New York, Dr. William Chardack implanted a pacemaker, designed and built by Wilson Greatbatch, an electrical engineer and inventor, in a 77-year old man with complete atrioventricular block, extending the patient's life by 18 months. This landmark event ushered in a new era of implantable cardiac pacemakers with batteries and leads of high reliability and increasing durability. Over the past half century, the field of electrophysiology and implantable devices for the management of cardiac conduction disturbances has evolved dramatically. Today's pacemakers include increasingly complex features such as telemetry monitoring, auto programmability, and hemodynamic sensors. New-generation leads present a sophisticated design with improved geometry and steroid-eluting tips to reduce chronic inflammation, maintaining a low pacing threshold and high sensing capability. The lithium iodide battery remains the mainstay of implantable pacemaker systems, exhibiting a multiple-year lifespan, slow terminal decay, and a reduced size and cost of production. Although Greatbatch's first successful pacemaker implantation remains a seminal scientific contribution to modern cardiovascular disease management, emerging developments in this field may challenge its preeminence. Important challenges such as imaging compatibility, lead durability, and infection prevention are being addressed. Novel concepts such as leadless and biologic pacing are under active investigation. In conclusion, Greatbatch's historic achievement 50 years ago reminds us that technologic progress is timeless, as efforts to enhance clinical outcomes and the quality of life continue unimpeded into the 21st century.

Medical therapy in acute coronary syndromes: which medicines and at what doses?

Acute coronary syndrome (ACS) occurs when plaque rupture in a coronary artery is superimposed with thrombus formation. This accounts for 1.7 million hospital admissions in the United States annually and significant morbidity and mortality. Although there are advantages to an invasive approach to treating patients with ACS, the role of medical therapy is vital as an adjunctive treatment to reperfusion therapies and in stabilizing ruptured plaques and modifying the metabolic milieu that predisposes to plaque formation and rupture. This article reviews the most important drug classes for medical treatment of ACS patients, as well as optimal doses. This is an exciting time to be involved in the field of cardiovascular medicine, as we continue to see profound improvement from medical therapy in the morbidity and mortality associated with ACS.

Septal infarction and complete heart block following percutaneous coronary intervention of the left anterior descending coronary artery.

Occlusion of septal perforator arteries may lead to angina, myocardial infarction, arrhythmias, atrio-ventricular (AV) block and heart failure. Percutaneous coronary intervention (PCI) on septal arteries has been performed to alleviate anginal symptoms. We describe the case of a patient who underwent routine PCI of his proximal left anterior descending (LAD) artery complicated by septal artery occlusion, septal infarction and the development of complete heart block. The patient underwent successful balloon angioplasty of the first septal perforator which led to partial recovery of AV conduction and hemodynamic stabilization.