Correlation of mean pulmonary artery wedge pressure, left atrial dimention, and PTF-V1 in patients with acute myocardial infarction

Compromised left atrial function and increased size predict raised cavity pressure: a systematic review and meta-analysis

AIM

This meta-analysis assesses left atrial (LA) cavity and myocardial function measurements that predict pulmonary capillary wedge pressure (PCWP).

METHODS

PubMed-MEDLINE, EMBASE, Scopus, Google Scholar and the Cochrane Central Registry were searched up to December 2018 for studies on the relationship of LA diameter, LA indexed volume (LAVI max, LAVI min), peak atrial longitudinal (PALS), peak atrial contraction (PACS) strain and total emptying fraction (LAEF) with PCWP. Eighteen studies with 1343 patients were included. Summary sensitivity and specificity (with 95% CI) for evaluation of diagnostic accuracy and the best cut-off values for different LA indices in predicting raised PCWP were estimated using summary receiver operating characteristic analysis.

RESULTS

The pooled analysis showed association between PCWP and LA diameter: Cohen's d = 0·87, LAVI max: d = 0·92 and LAVI min: d = 1·0 (P<0·001 for all). A stronger correlation was found between PCWP and PALS: d = 1·26, and PACS: d = 1·62, total EF d = 1·22 (P<0·0001 for all). PALS ≤19% had a summary sensitivity of 80% (65-90) and summary specificity of 77% (52-92), positive likelihood ratio (LR+) 3·74, negative likelihood ratio (LR-) <0·25 and DOR > 15·1 whereas LAVI ≥34 ml m^-2 had summary sensitivity of 75% (55-89) and summary specificity 77% (57-90), with LR+ >3, LR- 0·32 and DOR >10·1.

CONCLUSIONS

Compromised LA myocardial function and increased size predict raised cavity pressure. These results should assist in optimum follow-up of patients with fluctuating LA pressure.

Supraventricular tachyarrhythmias in acute myocardial infarction

Onset of atrial tachycardia, flutter or fibrillation occurred in 11% of 274 consecutive patients with acute myocardial infarction (AMI). Atrial tachycardia started about 24 hours and atrial flutter/fibrillation about 72 hours after onset of AMI symptoms. Left heart failure, diagnosed as pulmonary rales or frank pulmonary edema, was not more common in these patients before onset of tachyarrhythmias than among the rest of the patients. On the other hand, a notching of the P wave in lead CR-was significantly more common in the patients with atrial fibrillation (67%). In most of these cases the terminal P force in lead CR1 was not negative as in so-called left atrial enlargement. These findings suggest that atrial conduction disturbances might be a basis of atrial fibrillation in AMI.

Asymptomatic coronary artery disease detection: update 1996. A screening protocol using 16-lead high-resolution ECG, ultrafast CT, exercise testing, and radionuclear imaging

The authors have proposed a new four-step screening algorithm to detect asymptomatic coronary artery disease (CAD) in flight school candidates, cadets, and rated flyers of the Unites States Air Force (USAF). In step 1, the USAF Armstrong Laboratory (USAF/AL) risk profile and improved 16-lead high-resolution electrocardiogram/vectorcardiogram will be recorded at baseline. On routine follow-up evaluations, quantitative serial comparisons will be performed by the method of Kornreich. In step 2, beginning with flight school candidates and cadets, all three groups will be studied by the ultrafast computed tomograph (CT) protocol. Those candidates positive for coronary calcium will be studied by coronary angiography and ventriculography, and their eligibility for continued rated flight status will be determined by present criteria. In step 3, those candidates negative for coronary calcium by ultrafast CT will then be screened by the newly defined and improved high-sensitivity treadmill exercise test criteria. In step 4, candidates with a positive treadmill exercise test result, or who are also found in the upper quintile of the USAF/AL risk profile, wild also have exercise nuclear wall motion studies and perfusion scans. If these are abnormal and suggestive of myocardial ischemia, this subset will also be studied by heart catheterization and coronary angiography, and their eligibility for continued rated flight status will be determined by present criteria. The incidence of coronary calcium/no calcium for each degree of stenosis in the 6,000 flyers in each quintile was used to develop the following projections: (1) that more than 3 of 4 rated flyers with unsuspected CAD, and (2) more than 9 of 10 with severe flow-limiting CAD can be identified by these upgraded screening procedures. Evidence is herein presented that these enhancements will result in a major (5-8-fold) increase in case finding of this disease. Based on the estimate of four lost high-performance aircrafts per year from sudden incapacitation of the pilot due to CAD, when this four-step screen is fully operational, it can be expected to reduce the $80 million annual losses to the United States government from CAD by 85%, a savings of $68 million per year.

Significance of signal-averaged P-wave changes during exercise in patients with coronary artery disease and correlation with angiographic findings

The maximal P-wave duration in all time-aligned leads, and the maximal P-wave amplitude in leads V5 and V6 were measured on a 12-lead, signal-averaged electrocardiogram during the recovery period of an exercise stress test (EST). The study group consisted of 75 patients with coronary artery disease (CAD) documented by greater than or equal to 50% diameter stenosis in 1 or more arteries and a control group of 47 subjects, 15 of them young volunteers and 32 with no or minimal coronary atherosclerosis and normal left ventricular function. All subjects underwent a symptom limited EST, with use of the Ellestad protocol. Signal-averaged P waves recorded before exercise, and for the first 6 minutes in recovery were measured using a 5x magnifier. The mean P duration before exercise in the control group was 107 +/- 16 ms (+/- 1 standard deviation) and 111 +/- 15 ms at the third minute of recovery, (p less than 0.001). In patients with CAD it was 112 +/- 12 and 129 +/- 19 ms (+/- 1 standard deviation), p less than 0.001, respectively. Differences in P-wave duration were found to be statistically significant (p less than 0.001) throughout recovery in the group with CAD when compared with control and maximal values at the third minute. The increase in P-wave duration (greater than or equal to 20 ms) was used as an additional parameter to exercise-induced ST-segment depression, ST elevation, or anginal pain for the test interpretation. The sensitivity increased from 57 to 75% and the specificity decreased from 85 to 77%.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiographic diagnosis of chamber enlargement

The purpose of this article is to review the changing role of the electrocardiogram in the diagnosis of cardiac chamber enlargement. Electrocardiographic criteria for the diagnosis of ventricular hypertrophy and atrial enlargement are reviewed in relation to autopsy, angiographic, echocardiographic and imaging findings. The electrocardiographic theory underlying the recognition of hypertropphy or dilation incorporates a number of sound physical principles that may lead to meaningful correlations with the tissue mass, chamber diameter and intracardiac blood volume. However, there are limiting factors related to the variable orientation of the heart in the chest, variable extracardiac factors and nonspecificity of each depolarization and repolarization abnormality used in the diagnosis of hypertrophy or dilation. This explains the superiority of the new noninvasive methods, in particular echocardiography, in the diagnosis of hypertrophy. Echocardiography is superior to electrocardiography in the detection of mild hypertrophy, and is more useful in the serial follow-up of changes during progression or regression of chamber enlargement.

Prospective study comparing different echocardiographic measurements of pulmonary capillary wedge pressure in patients with organic heart disease other than mitral stenosis

In 25 patients with cardiac disease, but free of left ventricular inflow obstruction, the electrocardiogram and M-mode echocardiogram of the aortic root, left atrium and both the mitral and the aortic valves were obtained simultaneously with the pulmonary artery wedge pressure (PAWP) during right heart catheterization. The echocardiographic measurements of the left atrial size, PR-AC interval, left atrial emptying index and the ratio between the electrocardiographic Q wave to mitral valve closure (Q-MVC) and between aortic valve closure to the mitral E point (AVC-E) were correlated to the pulmonary artery wedge pressure by means of linear regression analysis. A formula in which PAWP = 36.6 (Q-MVC/AVC-E)-- 2 was prospectively used to study the measured pressure in the current group of patients. The pulmonary artery wedge pressure derived from these latter measurements correlated well with the invasive measurement of this pressure (r = 0.91). The pulmonary artery wedge pressure calculated by echocardiography differed from the pulmonary artery wedge pressure measured by catheterization by 3 mm Hg or less in 19 of the 25 patients, by 4 mm Hg or less in 22 patients and by 6 mm Hg or less in 24 patients. Although the correlation between the (Q-MVC/AVC-E) ratio and measured pulmonary artery wedge pressure was highly significant (r = 0.91, probability [p] less than 0.001, n = 25), the left atrial emptying index, PR-AC and left atrial size revealed poor correlation coefficients (r = 0.45, r = 0.45 and r = 0.56 [p less than 0.05]), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiographic recognition of left atrial enlargement

The ECG is widely used as a screening test for left atrial enlargement (LAE). Surprisingly, the most widely used criterion of LAE, the P-terminal force in lead V1 (PTF-V1) has not been systematically evaluated to determine the optimal level of PTF-V1 for detection of LAE in clinical populations. Accordingly, we examined the relationship between PTF-V1 and left atrial size by echocardiogram in 361 patients and performed a Bayesian analysis of test performance in populations with a varying prevalence of LAE. As PTF-V1 increased from greater than or equal to 0.03 to greater than or equal to 0.08, sensitivity in the 82 patients with LAE (LA dimension greater than 40 mm) fell from 51% to 23%, and specificity rose from 70% to 93%. In our study population (LAE prevalence = 23%), diagnostic performance of criteria was: PTF-V1 greater than or equal to 0.03 greater than or equal to 0.04 greater than or equal to 0.05 greater than or equal to 0.06 greater than or equal to 0.08 Positive Predictive Accuracy 33 46 52 58 50 Negative Predictive Accuracy 83 83 84 83 80 Per Cent Correct Diagnosis 66 76 78 80 77 Positive predictive accuracy and per cent correct diagnosis improved progressively as PTF-V1 rose from greater than or equal to 0.03 to greater than or equal to 0.06, but fell at greater than or equal to 0.08. Applying our sensitivity and specificity data to Bayesian analysis, PTF-V1 greater than or equal to 0.06 performed best in all populations with prevalence of LAE less than or equal to 50%. We conclude that use of PTF-V1 greater than or equal to 0.06 is superior to the standard criterion of PTF-V1 greater than or equal to 0.04 for all purposes ranging from screening of a general population to evaluation of diseased individuals whose likelihood of LAE ranges up to 50%.

Evaluation of changes in left ventricular end-diastolic pressure by left atrial two-dimensional echocardiography

Two-dimensional echocardiography (2DE) measurements of left atrial (LA) cross-sectional areas were compared in closed-chest dogs with concurrent high-fidelity recordings of left ventricular end-diastolic pressure (LVEDP) measurements. One hundred forty-three simultaneous determinations of LVEDP and end-diastolic as well as end-systolic LA cross-sectional areas were obtained in eight dogs during control, after coronary artery occlusion, and following alterations in LV preload and afterload. Correlation coefficients for LVEDP versus LA end-diastolic cross-sectional area ranged from 0.85 to 0.97 in the eight dogs, with standard errors of estimate from 1.89 to 5.43 mm Hg. These findings suggest that 2DE measurements of changes in LA size may facilitate noninvasive evaluation of alterations in LVEDP in patients with LV failure or undergoing interventions.