Increased prevalence of significant tricuspid regurgitation in patients with transvenous pacemakers leads.

Transvenous pacemaker leads are associated with an increased prevalence of tricuspid regurgitation. This hemodynamic derangement should be considered as part of the clinical cost and complications of permanent pacemaker implantation.

Recurrent systemic embolization caused by aortic thrombi.

The aorta is a commonly unrecognized source of systemic embolization. Transesophageal echocardiography is a reliable method for visualization of the intima of the thoracic aorta and identification of aortic thrombi. Balloon embolectomy of the aorta can be used to remove thrombi and prevent further embolic events.

Stress echocardiography.

Stress echocardiography has become an accepted noninvasive method for the diagnosis of coronary artery disease. Stress echocardiography is more sensitive than exercise electrocardiography and as sensitive and specific as radionuclide perfusion studies for detecting coronary artery disease. Pharmacologic stress echocardiography using dobutamine also has excellent diagnostic accuracy for patients who are unable to exercise. Dobutamine stress echocardiography can provide prognostic data to determine perioperative cardiac risks in patients who are undergoing vascular surgery.

Color flow and conventional echocardiography of the Marfan syndrome.

Imaging and color flow Doppler echocardiography are an integral part of any evaluation of a patient with the Marfan syndrome. The major cardiovascular manifestations of this condition are aortic dilation, which may involve the proximal and distal aorta, aortic regurgitation, aortic dissection, mitral valve prolapse, and mitral regurgitation. Patients who have the Marfan syndrome should have serial echocardiograms to measure aortic root diameter carefully at the sinuses of Valsalva and subsequent levels (sinotubular junction, arch, descending and abdominal aorta). Additionally, color Doppler echocardiography assists in the diagnosis of aortic dissection and facilitates evaluation of the severity of aortic and mitral regurgitation that commonly complicate the Marfan syndrome. The risk of aortic dissection, which is the most serious manifestation of the Marfan syndrome, increases as the aorta enlarges. Therefore, elective composite graft surgery is recommended when the aortic root size reaches 60 mm, regardless of symptom status, or 55 mm in the presence of severe aortic regurgitation. Surgical replacement of the aortic root with a composite graft does not end the disease process. Color flow Doppler is useful in the diagnosis of dehiscence of the conduit sewing ring, coronary artery aneurysm, distal aortic dissections, and prosthetic valve dysfunction.

Evaluation of formulas for estimating the final size of acute myocardial infarcts from quantitative ST-segment elevation on the initial standard 12-lead ECG.

Previously developed formulas for predicting the final QRS estimated sizes of acute myocardial infarcts from the initial ST segment deviation are tested. The population contains patients with either anterior or inferior infarcts from two hospitals in Copenhagen, Denmark. The formula for anterior location that considers only the number of ECG leads with ST elevation achieved a high correlation (r = 0.70). However, the formula for inferior location that considers the quantity of ST elevation in inferior leads achieved a lower value (r = 0.52). Empiric modifications of this formula were constructed that considered either the quantity of ST elevation in (A) or the number of (B) involved non-inferior leads. Each modification achieved improvement in correlation with QRS estimated MI size in the original population (A: r = 0.63 and B: r = 0.65), and also in an independent test population (A: r = 0.57 and B: r = 0.62). These results suggest that the formula of Aldrich et al. for anterior location is valid for clinical application, but that further studies are required to determine if a comparably accurate method can be developed for inferior MI.

Use of initial ST-segment deviation for prediction of final electrocardiographic size of acute myocardial infarcts.

The decision to administer thrombolytic therapy for limitation of acute myocardial infarction (AMI) size must occur when only the history, physical examination and 12-lead electrocardiogram of a patient are available. A method that could quickly assess the amount of jeopardized myocardium would greatly aid the physician. This study developed formulas from 68 anterior and 80 inferior AMI patients using the extent of initial ST-segment deviation (ST delta) to predict the final AMI size estimated by the Selvester QRS score in a population not receiving reperfusion therapy. Inclusion required: initial anterior or inferior AMI; admission electrocardiogram less than or equal to 8 hours after the onset of symptoms with evidence of epicardial injury; elevated creatine kinase-MB; a predischarge electrocardiogram taken greater than or equal to 72 hours after admission; and no AMI extension before the predischarge electrocardiogram. The extent of epicardial injury was quantified by counting the number of leads with greater than or equal to 0.1 mm ST delta, by the sum (sigma) of ST delta in all leads and by the sigma ST delta in the lead groups associated with each AMI location. These results were compared to the AMI size estimated from the predischarge electrocardiogram. Univariable and multivariable analyses generated these formulas for AMI size: anterior = 3[1.5 (number leads ST increases) - 0.4]; inferior = 3[0.6 (sigma ST increases II, III, aVF) + 2.0]. Thus, formulas based on quantitative measurements of ST delta on the admission electrocardiogram are predictive of final QRS-estimated AMI size, and may be useful in determining the efficacy of acute reperfusion therapy.

Identification of the optimal electrocardiographic leads for detecting acute epicardial injury in acute myocardial infarction.

Current coronary care electrocardiographic (ECG) monitoring techniques are aimed at detection of cardiac arrhythmias rather than myocardial ischemia. However, in patients with acute myocardial infarction (AMI) who undergo reperfusion therapy, monitoring ST-segment deviation could provide an early noninvasive indicator of coronary artery reocclusion. In this study, the admission 12-lead ECGs of patients with initial AMI were used to propose optimal lead locations for ST-segment monitoring. The study population was selected from consecutive Duke University Medical Center admissions during 1965 to 1981 who met the following inclusion criteria: chest pain for no more than 8 hours, initial AMI documented by ECG and 3 of 4 enzyme criteria, greater than or equal to 0.1 mV (1 mV = 10 mm) of ST elevation in at least 1 of the standard 12 leads (not aVR) on admission ECG, and no ECG evidence of conduction disturbances, ventricular hypertrophy or tachycardia. ST-segment deviation was quantified; AMI location was assigned based on the lead with maximal deviation. Of the 80 patients who had an inferior AMI, lead III was both the most frequent location for ST elevation (94%) and the most common site with maximal ST deviation. Lead V2 had the highest incidence of ST-segment depression (60%). In the 68 patients who had an anterior AMI, lead V2 had the highest frequency of ST elevation (99%). Leads V2 and V3 were the most common sites of maximal elevation. Thus, for monitoring ST deviation, leads III and V2 may be superior to leads II and V1, which are commonly used in arrhythmia monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)