Features of an exceptionally narrow QRS data set
Autor: | Daniel Childers, Anthony Holmes, Rory Childers, Masha Kocherginsky, Joseph J. Pariser |
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Rok vydání: | 2008 |
Předmět: |
African american
medicine.medical_specialty business.industry Models Cardiovascular Reproducibility of Results Sensitivity and Specificity Confidence interval QRS complex Electrocardiography Narrow qrs Duration (music) Heart Rate Internal medicine Heart rate Cardiology medicine Positive relationship Humans Computer Simulation Cardiology and Cardiovascular Medicine business |
Zdroj: | Journal of electrocardiology. 41(6) |
ISSN: | 1532-8430 |
Popis: | Little attention has been directed to the characteristics of electrocardiograms (ECGs) with brief QRS durations (BD).From a database of 859,977 computer-analyzed (Marquette 12SL, GE Healthcare, Milwaukee, WI, USA) ECGs of 216,148 patients, 1805 patients (data set of BD: 19,718 ECGs; age,18 years, unpaced), had, in at least one ECG, a QRS duration of less than 62 milliseconds, a prevalence of 0.8%.The QRS duration ranged from 46 to 188 milliseconds; values fluctuated between excessive brevity and the traditionally normal (80-95 milliseconds), with many values in the 60's. The average age at first acquisition was 56 years (range, 18-96 years); 1371 were female (76%) and 433 were males (24%); and 416 were white (23%), 1243 African American (69%), 109 other (6%). The summed 12-lead QRS amplitude (SigmaQRS) ranged from 2800 to 32,929 microV (mean +/- SD, 11,154 +/- 4101), and heart rate ranged from 40 to 269 (98 +/- 26). There was a statistically positive relationship between QRS duration (in the range 52-105 milliseconds) and SigmaQRS (P0001): for each 1000 microV increment, duration increased by 0.7 milliseconds (95% confidence interval [CI], 0.66-0.73 milliseconds). Conversely, for each 5-millisecond increment in duration, SigmaQRS increased by 475 microV (95% CI, 450-498 microV). There was an inverse relationship between QRS duration and heart rate (P.0001): for every 10 beat rate increase, the duration dropped by 1.14 milliseconds (95% CI, 1.09-1.19 milliseconds). An additional data set of normal QRS durations ND consisted of 2902 subjects, none of whose 40,327 ECGs showed a QRS duration less than 62 milliseconds; 2.8% of ND ECGs had durations in the 62-69 millisecond range, 26% in BD. Sinus tachycardia was 43% in BD and 24% in ND. The average age of ND was 58 years (range, 18-100 years); 44% were male and 56% female; and 39% were white and 57% were African American. A positive relationship between duration and amplitude was found among ND subjects as well: for each 1000 point increase in SigmaQRS, duration increased by 0.45 milliseconds (P.0001; 95% CI, 0.42-0.47 milliseconds). The duration amplitude relationship did not hold for durations greater than 105 milliseconds in either data set.Over the full extended span of QRS durations (46-106 milliseconds), the value of the latter is directly related to the total summed amplitude of the 12-lead QRS. An inverse relationship is demonstrable with heart rate. |
Databáze: | OpenAIRE |
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