Article Figures & Data
Figures
- FIGURE 1.
Electrocardiogram waveforms of single heart beat in sinus rhythm. Normal duration of PR interval is 120–200 ms. Width of normal QRS complex is <100 ms. Normal duration of QT interval corrected to heart rate is <440 ms. Standard electrocardiogram paper is 1-mm grid. As annotated, horizontally 1 small square is 0.04 s and 1 large square is 0.2 s; thus, 5 large boxes (25 small boxes) is 1 s. Trace moves at speed of 25 mm/s, and 10 small squares on vertical axis equates to 1 mV.
- FIGURE 2.
(A) Normal sinus rhythm with R–R interval of approximately 1 s (60 bpm). (B) Sinus tachycardia with R–R interval of approximately 2 s (>120 bpm). Approximately 2.2 large squares indicates that heart rate is 136 bpm (300/2.2).
- FIGURE 3.
(A) Rhythm strip demonstrating first-degree atrioventricular block with PR interval of >200 ms. (B) Rhythm strip demonstrating second-degree atrioventricular block with progressive lengthening of PR interval and 2 P waves per R–R interval (arrows). (C) Rhythm strip demonstrating third-degree atrioventricular block. Atrioventricular dissociation results in no QRS but prominent P wave. Absence of Q wave allows visualization of repolarization of atria (arrow).
- FIGURE 4.
(A) Atrial fibrillation with rapid ventricular response. No P waves are seen, and ventricular rate is irregular and rapid. QRS complex is narrow. (B) Atrial flutter with sawtooth flutter wave (arrows). (C) VF with no organized QRS complex. (D) Ventricular ectopic beats. (E) Ventricular pacing spikes (arrow) and QRS morphology associated with left bundle branch block.
- FIGURE 5.
(A) Electrocardiogram appearance of myocardial ischemia spectrum. Clockwise: normal (P QRS T), upsloping ST depression (>1.5 mm); horizontal ST depression (>1 mm); downsloping ST depression (>1 mm); and ST elevation. (B) Electrocardiogram appearance of myocardial infarction spectrum. Clockwise: normal, hyperacute infarction (T wave); transmural infarction (ST elevation); necrosis (ST elevation, Q waves, and T wave inversion); necrosis/fibrosis (Q waves and T wave inversion); and fibrosis (Q wave and upright T wave).
- FIGURE 6.
(A) Electrocardiogram appearance at baseline for patient with ischemic heart disease. (B) Stress electrocardiogram demonstrating inferolateral upsloping ST depression. (C) Poststress electrocardiogram demonstrating inferolateral horizontal ST depression, which indicates myocardial ischemia.
