Clinical investigation: Utility of left ventricular end diastolic diameter in the prediction of susceptibility to ventricular tachyarrhythmias.

BACKGROUND: Prior studies have shown the utility of using both QRS duration and QT dispersion (QTd) as predictors of risk for ventricular tachyarrhythmias (VA). Lengthening of the QRS duration represents dyssynchrony of regional myocardial wall contraction, and increased QTd similarly represents variations in myocardial repolarization. We sought to examine the left ventricular end diastolic diameter (LVEDD) as a predictor of VA susceptibility. METHODS: Eighty-eight patients referred for electrophysiologic (EP) studies were evaluated. EP testing was performed using a standard protocol of up to three extrastimuli. QTd and QRS duration analyses were performed in a blinded manner. Values were defined as abnormal if QRS duration>120 ms, QTd>60 ms, and LVEDD>6 cm. RESULTS: Of 88 patients (65 males; 23 females; mean age 67+/-15 years), 33 were inducible by EP testing. Patients with either increased QRS duration or QTd are shown to be at greater risk for VA inducibility. LVEDD is a strong predictor of inducibility for VA (p<0.02 between inducible and non-inducible patients). LVEDD in combination with QRS duration and QTd, further strengthens predictability for VA (p<0.03 for QRS duration and p<0.02 for QTd) with a trend towards inducibility as each value increases. Combination of the three parameters of QRS duration, QTd, and LVEDD was 91% sensitive for the identification of those patients inducible for VA. CONCLUSION: The LVEDD is an echocardiographic value that strongly predicts VA inducibility, and when combined with QRS duration and QTd, identifies patients at higher risk for these tachyarrhythmias.

Diagnosis of suspected cardiac echinococcosis with negative serologies: role of transthoracic, transesophageal, and contrast echocardiography.

The early recognition and treatment of hydatid disease of the heart is important as it can result in potentially lethal complications. We present the clinical and echocardiographic features of a 71 year old Afghanistani man who presented with left-sided chest pain. Transthoracic (TTE), transesophageal (TEE), and contrast echo demonstrated a calcified cystic structure within the distal anterior septum consistent with an echinococcal cyst, despite negative serologies. Treatment strategies for this patient are discussed.

Should the initiation of antiarrhythmic therapy for atrial fibrillation occur in the hospital or out of the hospital?: a review of the literature.

BACKGROUND: Initiation of antiarrhythmic therapy for atrial fibrillation is a key step in the treatment of this disorder. Much controversy remains as to the risks and benefits of initiating therapy as an inpatient versus an outpatient. OBJECTIVE: To explore the various issues of debate and to determine the importance and validity of these various issues when it comes to the evaluation of patients for in- versus out-of-hospital initiation of antiarrhythmic therapy for atrial fibrillation. METHODS: A MEDLINE search of English language journal articles since 1966 and a hand search of bibliographies included in pertinent retrieved articles was undertaken. Articles used included review articles, retrospective studies, and meta-analyses. RESULTS: The literature is full of articles for and against outpatient initiation of antiarrhythmic therapy. One side feels that the risks of antiarrhythmic therapy initiation are serious enough in all patients and easy enough to reverse or ameliorate if the patient is in the safety of the monitored hospital setting. The other side argues that these complications are infrequent enough except in certain commonly identifiable patients, that not all need hospitalization during antiarrhythmic initiation. The issues at the heart of the dispute include: the presence or absence of underlying heart disease; the period of monitoring after initiation of therapy; the choice of antiarrhythmic agent used; and even the seriousness and prevalence of the arrhythmia which can be induced. CONCLUSIONS: The issue of in versus out-of-hospital initiation of antiarrhythmic therapy for atrial fibrillation remains a widely disputed topic. Many factors come under consideration when this topic is studied. At present, we recommend that patients with significant structural heart disease, conduction disease, and/or QT prolongation be strongly considered for in-hospital initiation of antiarrhythmic medications. Further prospective studies are necessary to assess the magnitude of the difference of initiating antiarrhythmic therapy as an inpatient versus as an outpatient.