Methodology of ECG Interpretation in the Dalhousie Program; NOVACODE ECG Classification Procedures for Clinical Trials and Population Health Surveys^[*]

Abstract

The Dalhousie ECG Program was designed specifically for the needs of epidemiologic studies, health surveys, and clinical trials. The program logic is dynamic in that it can accommodate any combination of ECG leads, record length and sampling rate. The NOVACODE module of the program classifies ECGs according to the Minnesota Code, supplemented with new sets of logic criteria for conduction defects, acute myocardial infarction, and serial ECG changes. Improved statistical models are incorporated for enhanced detection of myocardial infarction using the Cardiac Infarction Injury Score, and for quantification of left ventricular mass estimation. It is anticipated that these program improvements will enhance its utility particularly in monitoring progression and regression of cardiac involvement in hypertensive and ischemic heart disease, and in the assessment of the effectiveness of intervention on cardiovascular disease risk factors.

Key-Words

ECG Criteria – Myocardial Infarction - Left Ventricular Hypertrophy - QT Interval – Conduction Defects

^* Supported in part by the Medical Research Council of Canada (MRC PG-30) and the Nova Scotia Heart Foundation.

• REFERENCES

• 1 Rautaharju PM, Blackburn H. The exercise electrocardiogram: Experience in analysis of “noisy” cardiograms with a small computer. Am Heart J 1965; 69: 515-20.
• 2 Rautaharju PM. Hybrid and small special-purpose computers in electrocardiographic, ballistocardiographic and pulse wave research. Ann New York Acad Sci 1965; 126: 906-18.
• 3 Rautaharju PM. Deterministic type waveform analysis in electrocardiography. Ann New York Acad Sci 1966; 128: 939-54.
• 4 Wolf HK, Maclnnis PJ, Stock S, Helppi RK, Rautaharju PM. Computer analysis of rest and exercise electrocardiograms. Comp Biomed Res 1972; 05: 329-46.
• 5 Wolf HK, Maclnnis PJ, Stock S, Helppi RK, Rautaharju PM. The Dalhousie Program: A comprehensive analysis program for rest and exercise electrocardiograms. In: Zywietz C, Schneider B. (eds). Computer Application on ECG and VCG Analysis. Amsterdam: North-Holland Publ Comp; 1973: 231-40.
• 6 Rautaharju PM, Broste S, Prineas R, Crow R, Eifler WJ, Furberg C. Quality control procedures for the resting electrocardiogram in the Multiple Risk Factor Intervention Trial. J Controlled Clin Trials 1986; 07: 46S-65S.
• 7 Blackburn H, Keys A, Simonson E, Rautaharju PM, Punsar S. The electrocardiogram in population studies. A classification system. Circulation 1960; 21: 1160-75.
• 8 Rautaharju PM. Electrocardiogram in epidemiology and clinical trials. In: Mac-Farlane PW, Lawrie TDV. (eds). Comprehensive Electrocardiology. New York: Pergamon Books Ltd; 1988: 1219-66.
• 9 Prineas RJ, Crow RS, Blackburn H. The Minnesota Code Manual of Electrocardiographic Findings: Standards and Procedures for Measurement and Classification. Boston Mass: Wright PSG Inc; 1982
• 10 Rautaharju PM, Prineas RJ, Eifler WJ. et al. for the Multiple Risk Factor Intervention Trial Research Group. Prognostic value of exercise ECG in men at high risk of future coronary heart disease. JACC 1986; 811: 1-10.
• 11 Crow RS, Prineas RJ, Jacobs Jr DR, Blackburn H. A new epidemiologic classification system for interim myocardial infarction from serial electrocardiographic changes. Am J Cardiol 1989; 64: 454-61.
• 12 Startt RHSelvester. Comprehensive multilead normal ECG database for the next few decades – A position paper. In: Willems JL, van Bemmel JH, Zywietz C. (eds). Computer ECG Analysis: Towards Standardization. Amsterdam: Elsevier Science Publ; 1986: 221-6.
• 13 Rautaharju PM, LaCroix AZ, Savage DD. et al. Electrocardiographic estimate of left ventricular mass vs radiographic cardiac size and the risk of cardiovascular disease mortality in the epidemiologic follow-up study of the First National Health and Nutrition Examination Survey. Am J Cardiol 1988; 62: 59-66.
• 14 Rautaharju PM, Savage DD, Madans JH. et al. Dependence of ECG-LVH criteria on constitutional variables. In: Abel H. (ed). Electrocardiology 1988, Proc 15th Internat Congress on Electrocardiology. Wiesbaden. 1989: 207-10.
• 15 Rautaharju PM, LaCroix AZ, Savage DD. et al. Heart size estimates indexed optimally to body and chest size. I. The effect of age and hypertensive status. Am J Noninvasive Cardiol 1990; 04: 104-14.
• 16 Davignon A, Rautaharju PM, Boisselle E, Soumis F, Megelas M, Choquette A. Normal ECG standards for infants and children. Ped Cardiol 1979; 01: 123-31.
• 17 Rautaharju PM, Warren J, Jain U, Wolf HK, Nielsen CL. Cardiac Infarction Injury Score: An electrocardiographic coding scheme for ischemic heart disease. Circulation 1981; 6412: 249-56.
• 18 Willems JL, Willems R, Bijnens I, Doerr R, Verstraete M. Value of electrocardiographic scoring systems for the assessment of thrombolytic therapy in acute myocardial infarction. (subm. for publ.).
• 19 Startt RHSelvester, Sanmarco ME, Solomon JC, Wagner GS. The ECG: QRS change. In: Wagner GS. (ed). Myocardial Infarction: Measurement and Intervention. Developments in Cardiovascular Medicine (vol 14). The Hague: Martinus Nijhoff; 1982: 23-50.
• 20 Willems JL, Robles de EOMedina, Bernard R. et al. Criteria for intraventricular conduction disturbances and pre-excitation. JACC 1985; 516: 1261-75.
• 21 Rautaharju PM, Prineas RJ, Warren JW, Calhoun HP. Estimation of QT prolongation: A persistent error in computer electrocardiography. J Electrocardiol. (in press).
• 22 Casale PN, Devereaux RB, Alonso DR, Campo E, Kligfield P. Improved sex-specific criteria of left ventricular hypertrophy for clinical and computer interpretation of electrocardiograms: validation with autopsy findings. Diagnostic Methods – Electrocardiography 1987; 7513: 565-72.
• 23 Wolf HK, Burggraf GW, Cuddy TE. et al. Prediction of left ventricular mass from the electrocardiogram. J Electrocardiol (in press).
• 24 Elamin MS, Mary DASG, Smith DR, Linden RJ. Prediction of severity of coronary artery disease using slope of submaximal ST segment/heart rate relationship. Cardiovasc Res 1980; 14: 681-91.
• 25 Okin PM, Kligfield P. Computer-based implementation of the ST-segment/heart rate slope. Am J Cardiol 1989; 64: 926-30.
• 26 Puddu PE, Jouve R, Mariotti S. et al. Evaluation of 10 QT prediction formulas in 881 middle-aged men from the seven countries study: Emphasis on the cubic root Fridericia’s equation. J Electrocardiol 1988; 21: 219-29.
• 27 Rautaharju PM, Smets P. Evaluation of computer-ECG programs. The strange case of the golden standard. Comp Biomed Res 1979; 1211: 39-45.
• 28 Rautaharju PM, Warren J, Prineas R, Smets PH. Optimal coding of electrocardiograms for epidemiologic studies. The performance of human coders – a statistical model. J Electrocardiol. 1979 13/1: 55-60.