Morphology of ventricular premature beats as an aid in the electrocardiographic diagnosis of myocardial infarction.

To determine whether morphologic analysis of ventricular premature beats (VPBs) can aid in the electrocardiographic diagnosis of myocardial infarction (MI), 12-lead electrocardiograms were evaluated in 760 consecutive patients who underwent cardiac catheterization, and 2-minute multiple-lead rhythm strips were evaluated in 515 of these patients. VPBs occurred in 58 patients; 21 had prior MI diagnosed by regional akinesia or dyskinesia on left ventricular cineangiography. Standard criteria were used to diagnose prior MI from the sinus beats of the electrocardiogram. Infarction was diagnosed from the morphology of a VPB when it had a QR or QRS pattern with Q wave greater than or equal to 0.04 second. Morphologic analysis of VPBs had a low sensitivity (29%) but high specificity (97%) and high predictive value (86%) for the diagnosis of MI. Sinus beats diagnosed MI with higher sensitivity (52%, and 69% if patients with left bundle branch block and left ventricular hypertrophy were excluded from analysis) than VPB morphologic analysis (p less than 0.05), but with similar specificity (97%) and predictive value (92%). Two patients with angiographic MI had no MI according to standard electrocardiographic criteria, but did have an MI manifest by VPB morphologic analysis. Despite low sensitivity, analysis of the morphology of VPBs may be useful for the diagnosis of MI when the morphology of sinus beats is not diagnostic. Therefore, VPB analysis is complementary to the standard electrocardiographic diagnosis of MI.

Prolapsed left atrium behind the left ventricular posterior wall: two dimensional echocardiographic and angiographic features.

Left atrial enlargement can usually be detected accurately using M mode echocardiography. However, in the presence of heart disease, asymmetric enlargement may lead to inaccurate assessment of left atrial size and shape. Pericardial effusion can usually be diagnosed on the basis of characteristic M mode echocardiographic findings. However, false positive patterns sometimes occur with the use of this single dimensional technique. Three patients with a greatly enlarged left atrium are described whose M mode echocardiogram suggested significant posterior pericardial fluid accumulation. In each patient, two dimensional echocardiography detected portions of a huge left atrium that prolapsed behind the left ventricular posterior wall and mimicked an isolated posterior pericardial effusion. In one case a right anterior oblique left ventricular cineangiogram suggested the presence of a ventricular septal defect or a false aneurysm of the left ventricle due to the prolapsed left atrium. Because two dimensional echocardiography can provide accurate spatial orientation with visualization of intracardiac structures in relation to one another in real time, it can identify the presence of left atrial prolapse and play an important role in the differential diagnosis of isolated echo-free spaces behind the left ventricle detected with M mode echocardiography.

Two-dimensional echocardiographic assessment of electrocardiographic criteria for right atrial enlargement.

Right atrial (RA) size was determined with two-dimensional echocardiography using the apical four-chamber view in 45 adult patients with various echocardiographic criteria for RA enlargement and in 25 normal controls. RA size varied from 11.4-24.0 cm2 (mean 16.1 cm2) in controls. RA enlargement (greater than or equal to 25 cm2) was found in only two of 11 patients with P pulmonale (predictive value [PV] = 18%) and one of five with prominent positive P-wave forces in lead V1 (PV = 20%). However, RA enlargement ws found in eight of eight patients with a qR pattern in lead V1 in the absence of clinical indications of coronary artery disease (PV = 100%). RA enlargement was also found in 13 of 28 patients with a total QRS amplitude in lead V1 of 6 mm or less and a threefold or greater ratio of total QRS amplitude in lead V2 relative to that in V1(V2/V1 greater than or equal to 3) (PV = 48%). A V2/V1 ratio of 4 or more detected 11 of 13 patients with RA enlargement, with six false-positive diagnoses (sensitivity = 85%, specificity = 60%, PV = 65%). The combination of total QRS amplitude in V1 of 4 mm or less, together with a V2/V1 ratio of 5 or more, detected six of 11 with RA enlargement, with one false-positive diagnosis (sensitivity = 46%, specificity = 93%, PV = 86%). We conclude that ECG criteria for RA enlargement that primarily use increased P-wave amplitude have a limited PV. The qR pattern in lead V1 appears to be extremely accurate in detecting RA enlargement. ECG criteria in leads V1 and V2 using decreased amplitude in leads V1 and a V2/V1 greater than or equal to 3 are of some value in detecting RA enlargement.

Detection of tricuspid regurgitation and estimation of central venous pressure by two-dimensional contrast echocardiography of the right superior hepatic vein.

Two-dimensional echocardiography (2DE) was utilized to visualize the right superior hepatic vein (RSHV) for detection of tricuspid regurgitation (TR) and estimation of central venous pressure (CVP). Patients were divided into two groups. Eighteen patients were placed in group I on the basis of typical clinical features of TR (five patients) or 2DE contrast evidence of TR (13 patients). Group II included 55 patients without TR. Maximal transverse dimension of RSHV of at least 1.8 cm (range 1.8 to 3.8 cm, mean 2.4 cm) identified all patients in group I (100% sensitivity). One patient in Group II had RSHV width of 2.1 cm (96% specificity). Predictive value was 95%. RSHV width ranged from 0.4 to 2.1 cm (mean 1.3 cm) in group II. Mean values for group I and II were significantly different (p less than 0.001). Linear regression analysis was utilized to compare CVP and maximal RSHV width in 42 patients (15 group I and 27 group II). The slope of the line was significantly different from zero (p less than 0.005); the correlation coefficient was 0.70. In patients with maximal RSHV width greater than 1.5 cm, the predictive value for elevated CVP (greater than 6 mm Hg) was 87% with 69% sensitivity and 78% specificity. In 13 group II patients with technically satisfactory 2DE but no distinctly visible RSHV, CVP ranged from 4 to 12 mm Hg with four elevated values (greater than 6 mm Hg). Predictive value of normal CVP in absence of visible RSHV was 69%. This study suggests that determination of maximal RSHV width is useful in detection of TR and may be helpful in estimation of CVP.