![]() ![]() Improper heart rhythms are sometimes a sign of an infarction (an abnormal heart rhythm), but they don’t always indicate a problem with the heart. People who have heart disease may experience Q waves in the heart rhythm. Abnormal Q waves are frequently observed in the early stages of an acute myocardial infarction. In general, if they are too broad or too deep (and have a surface area greater than 5 mm), they are pathogenic. The Q wave is an early stage of ventricular depolarization. IHD mortality and hospitalization can be predicted based on Q-waves in the ECG regardless of age, hypertension, diabetes, or renal function. Using echocardiography may be beneficial in diagnosing conditions other than differentials. If you have frequent Q waves, you may have had a silent myocardial infarction, normal variations, or other pathologic but noncoronary causes. A failure to recognize pseudo-infarct patterns can lead to electrolyte imbalances. If normal Q waves on the baseline ECG are abnormal, it is possible that they do not indicate permanent damage to myocardium. Lead V6 is the most common, but less common in V4-V6. The left lead of 75% of people contains small Q waves. The condition can be caused by an electrical imbalance. Pathological Q waves indicate that you have had a previous myocardial infarction. DOI:10.Pathological Q waves can typically indicate a recent or previous myocardial infarction. ![]() Myocardial infarction redefined-a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. Alpert JS, Thygesen K, Antman E, and Bassand JP.The Novacode criteria for classification of ECG abnormalities and their clinically significant progression and regression. Rautaharju PM, Park LP, Chaitman BR, Rautaharju F, and Zhang ZM.Universal definition of myocardial infarction. Thygesen K, Alpert JS, White HD, Joint ESC/ACCF/AHA/WHF Task Force for the Redefinition of Myocardial Infarction., Jaffe AS, Apple FS, Galvani M, Katus HA, Newby LK, Ravkilde J, Chaitman B, Clemmensen PM, Dellborg M, Hod H, Porela P, Underwood R, Bax JJ, Beller GA, Bonow R, Van der Wall EE, Bassand JP, Wijns W, Ferguson TB, Steg PG, Uretsky BF, Williams DO, Armstrong PW, Antman EM, Fox KA, Hamm CW, Ohman EM, Simoons ML, Poole-Wilson PA, Gurfinkel EP, Lopez-Sendon JL, Pais P, Mendis S, Zhu JR, Wallentin LC, Fernández-Avilés F, Fox KM, Parkhomenko AN, Priori SG, Tendera M, Voipio-Pulkki LM, Vahanian A, Camm AJ, De Caterina R, Dean V, Dickstein K, Filippatos G, Funck-Brentano C, Hellemans I, Kristensen SD, McGregor K, Sechtem U, Silber S, Tendera M, Widimsky P, Zamorano JL, Morais J, Brener S, Harrington R, Morrow D, Lim M, Martinez-Rios MA, Steinhubl S, Levine GN, Gibler WB, Goff D, Tubaro M, Dudek D, and Al-Attar N.No significant Q waves or STT abnormalities.Minor Q waves (shallow Q Marginal risk of ischemic injury / possible Q wave MI:.Q >= 40 ms and ST deviation Major Q waves: Q >= 50ms or Q >= 40 ms AND R/Q = 30 ms and ST deviation > 0.20 mV (minor Q waves with STT abnormalities).High risk of ischemic injury/ Q wave MI:.The Novacode system further classifies ischemic abnormalities in patients with no known history of myocardial infarction: Lead III often shows Q waves, which are not pathologic as long as Q waves are absent in leads II and aVF (the contiguous leads)įor those interested: the Minnesota Code Classification System for Electrocardiographic Findings contains a very extensive definition of pathologic Q waves.Absence of pathologic Q waves does not exclude a myocardial infarction!.Here we present the latest definition as accepted by the ESC and ACC.ĭefinition of a pathologic Q wave Any Q-wave in leads V2–V3 ≥ 0.02 s or QS complex in leads V2 and V3 Q-wave ≥ 0.03 s and > 0.1 mV deep or QS complex in leads I, II, aVL, aVF, or V4–V6 in any two leads of a contiguous lead grouping (I, aVL,V6 V4–V6 II, III, and aVF) R-wave ≥ 0.04 s in V1–V2 and R/S ≥ 1 with a concordant positive T-wave in the absence of a conduction defect The precise criteria for pathologic Q waves have been debated. In all other situations they usually persist indefinitely. as a result of percutaneous coronary intervention) stunned myocardial tissue can recover and pathologic Q waves disappear. ![]() However, if the myocardial infarction is reperfused early (e.g. Once pathologic Q waves have developed they rarely go away. Pathologic Q waves are not an early sign of myocardial infarction, but generally take several hours to days to develop. A myocardial infarction can be thought of as an elecrical 'hole' as scar tissue is electrically dead and therefore results in pathologic Q waves. They are the result of absence of electrical activity. Pathologic Q waves are a sign of previous myocardial infarction. ![]()
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