Ecg normal values by age

• Heart rate > 100 beats/min • Apparent • T wave inversions in V1-3 (“juvenile T-wave pattern”) • • Dominant R wave in V1 • RSR’ pattern in V1 • Marked sinus arrhythmia • Short PR interval (< 120ms) and QRS duration (<80ms) • Slightly peaked P waves (< 3mm in height is normal if ≤ 6 months) • Slightly prolonged QTc (≤ 490ms in infants ≤ 6 months) • Q waves in the inferior and left precordial leads Pathophysiology At birth, the right ventricle is larger and thicker than the left ventricle, reflecting greater physiological stresses placed upon it in utero (i.e. pumping blood through the relatively high-resistance pulmonary circulation). This produces an ECG picture reflecting that of a • T-wave inversions in V1-3 • Right axis deviation • Dominant R wave in V1 Conduction intervals (PR interval, QRS duration) are shorter than adults due to the smaller cardiac size. Heart rates are highest in neonates and infants and decrease with age:

Neonatal period Table 1. Normal limits for ECG parameters during neonatal period (Davignon et al) These reference values are the best available for the neonatal period. The intervals are 98% confidence intervals (the mean is presented in the parenthesis). Values without confidence interval are simply the 98 th percentile (i.e the upper reference limit). Age 16 years Heart rate (beats per minute) 93–155 (122) 91–158 (124) 90–166 (128) 106–182 (148) 120–179 (149) 105–185 (142) 107–168 (132) 90–151 (119) 73–137 (108) 65–133 (100) 63–129 (92) 66–120 (86) 50 – 120 Electrical axis (degrees) 58–168 (>135) 65–171 (>134) 76–168 (>133) 65–159 (110) 31–115 (75) 7–105 (60) 7–98 (54) 8–100 (55) 7–104 (55) 10–140 (66) 9–115 (61) 11–133 (58) -15 – 110 QRS duration 21–76 22–67 21–68 22–79 23–75 22–79 23–76 27–75 30–72 32–79 32–85 34–88 0.05 – 0.10 PR interval 79–160 (107) 81–139 (108) 75–137 (104) 73–138 (101) 73–130 (98) 74–145 (106) 73–156 (156) 82–148 (114) 85–161 (118) 90–164 (124) 87–171 (128) 92–175 (135) 0.12 – 0.20 Q-wave in III (mm) 0.1–5 0.1–5 0.1–5 0.1–5 0.1–5 <6.6 <6.3 <5.3 <4.2 <3.2 <2.7 <3.0 <3 R-wave in V1 (mm) 5–27 (14) 5–27 (15) 3–25 (13) 3–22 (11) 3–19 (10) 3–20 (10) 2–20 (9) 3–18 (9) 2–18 (8) 1–13 (7) 0.5–10 (6) 0.5–10 (5) 0.5 – 14 S-wave in V1 (mm) 0.5–23 (9) 0.5–21 (10) 0.5–17 (7) 0.5–12 (4) 0.5–13 (5) 0.5–17 (6) 0.5–18 (7) 1–21 (9) 2–22 (10) 3–24 (12) 3–26 (12) 3–22 (11) 0.5 – 23 R/S-ratio in V1 0.2–9.8 (2.3) 0.2–6.0 (2.0) 0.2–9.8 (2.8) 1.0–7.0 (2.9) 0.3–7.5 (2.3) 0....

Getty Cardiac stress tests look at how your heart reacts to the stress of an increased workload. There are several types of cardiac stress tests. But basically, the stress can come from two different stimuli—exercise or medicines. Exercise stress tests are the most common type. Doctors use chemical stress tests with medicines when people aren’t able to exercise. The standard test is an ECG—or electrocardiogram—stress test. An Items in the Interpretation There are several things doctors look at and use in their interpretation of heart stress test results. These items include: • Baseline ECG: This is a recording of your heart’s electrical activity at rest. Doctor’s look for any abnormalities that show up without any stress. This may include changes in rhythm or rate with shifts in position, such as sitting, standing or lying. • ECG changes: There are specific changes in the heart’s activity that can tell doctors about your heart health. When they are present during stress, it may mean your heart muscle isn’t getting enough oxygenated blood. • Presence of arrhythmias: Changes in heart rhythm may or may not mean anything. If they are present during stress, doctors will look at the type of change and how often it happened. They will also want to know whether the changes disappeared with rest. • Blood pressure response: Increases or decreases in blood pressure during stress can give doctors clues about your heart health. If systolic blood pressure drops by more than 10 mmHg, it ...

Ejection fraction is a measurement doctors use to calculate the percentage of blood that leaves your heart each time it contracts. As your heart beats, it pumps (ejects) blood into your body from the two lower muscular chambers, known as the left and right ventricles. Between beats, when your heart relaxes, the two ventricles fill up with blood. However, it takes more than a single contraction to pump all the blood out of a ventricle. Ejection fraction is a test your doctor can use to determine the percentage of blood that leaves the left ventricle each time your heart beats, and to understand how well your heart works. Ejection fraction can help diagnose heart failure. Generally, your left ventricle is the one measured for ejection fraction. It does the heavy lifting in your body, pumping blood to almost all your major organs. However, current An accurate left ventricle ejection fraction (LVEF) reading can be measured through a variety of imaging techniques. The most common ejection fraction testing measures include: • Echocardiogram. An • Cardiac MRI (C-MRI). A C-MRI is an image-based test that uses a magnetic field, radio waves, and a computer to create detailed images of the inside of your heart. • Cardiac catheterization. In • Cardiac nuclear medicine scan. Trace amounts of radioactive materials are injected into your bloodstream. They’re then detected by cameras that produce images of your heart and its mechanisms. • Cardiac CT scan. This X-ray procedure can give a r...

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Page 15 of 20 Pediatric EKG Interpretation Before you read the EKG, look for: • Patient age, as many values change with age • Standardization: Full standard is two large squares (1 mV, 10 mm) and half standard is one large square (0.5mV, 5 mm) • Paper speed: the standard is 25 mm/sec. The faster the paper speed the slower the HR will look and vice versa Basic EKG interpretation • Heart rate: The standard paper speed is 25 mm (5 large squares)/sec. This means that if the distance between two beats (R-R) is 5 large squares, the HR is 60 beat/min. If the distance between two beats is one large square, the HR is 300 beat/min. Two squares →150, 3 squares →100, 4 squares → 75, 5 squares → 60, 6 squares → 50 beat/min. The HR may be counted by simply dividing 300 by the number of the large squares between two heart beats (R-R). • Axis: Make sure to determine both P wave and QRS axes. Net summation of positive and negative deflection is used. Look for two perpendicular leads (usually lead I and aVF). When QRS is positive in both lead I and aVF, the axis is in the left lower qua...

• Heart rate > 100 beats/min • Apparent • T wave inversions in V1-3 (“juvenile T-wave pattern”) • • Dominant R wave in V1 • RSR’ pattern in V1 • Marked sinus arrhythmia • Short PR interval (< 120ms) and QRS duration (<80ms) • Slightly peaked P waves (< 3mm in height is normal if ≤ 6 months) • Slightly prolonged QTc (≤ 490ms in infants ≤ 6 months) • Q waves in the inferior and left precordial leads Pathophysiology At birth, the right ventricle is larger and thicker than the left ventricle, reflecting greater physiological stresses placed upon it in utero (i.e. pumping blood through the relatively high-resistance pulmonary circulation). This produces an ECG picture reflecting that of a • T-wave inversions in V1-3 • Right axis deviation • Dominant R wave in V1 Conduction intervals (PR interval, QRS duration) are shorter than adults due to the smaller cardiac size. Heart rates are highest in neonates and infants and decrease with age:

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Page 15 of 20 Pediatric EKG Interpretation Before you read the EKG, look for: • Patient age, as many values change with age • Standardization: Full standard is two large squares (1 mV, 10 mm) and half standard is one large square (0.5mV, 5 mm) • Paper speed: the standard is 25 mm/sec. The faster the paper speed the slower the HR will look and vice versa Basic EKG interpretation • Heart rate: The standard paper speed is 25 mm (5 large squares)/sec. This means that if the distance between two beats (R-R) is 5 large squares, the HR is 60 beat/min. If the distance between two beats is one large square, the HR is 300 beat/min. Two squares →150, 3 squares →100, 4 squares → 75, 5 squares → 60, 6 squares → 50 beat/min. The HR may be counted by simply dividing 300 by the number of the large squares between two heart beats (R-R). • Axis: Make sure to determine both P wave and QRS axes. Net summation of positive and negative deflection is used. Look for two perpendicular leads (usually lead I and aVF). When QRS is positive in both lead I and aVF, the axis is in the left lower qua...

Getty Cardiac stress tests look at how your heart reacts to the stress of an increased workload. There are several types of cardiac stress tests. But basically, the stress can come from two different stimuli—exercise or medicines. Exercise stress tests are the most common type. Doctors use chemical stress tests with medicines when people aren’t able to exercise. The standard test is an ECG—or electrocardiogram—stress test. An ECG stress test monitors your heart’s electrical activity during exercise. Medical staff will also monitor your blood pressure and breathing. The exercise stress comes from walking on a treadmill or pedaling a stationary bike. In a chemical test, the stress comes from a medicine that stimulates the heart. Chemical stress tests use heart imaging along with an ECG. The imaging is necessary because stress changes from drugs may not be detectable by ECG alone. Items in the Interpretation There are several things doctors look at and use in their interpretation of heart stress test results. These items include: • Baseline ECG: This is a recording of your heart’s electrical activity at rest. Doctor’s look for any abnormalities that show up without any stress. This may include changes in rhythm or rate with shifts in position, such as sitting, standing or lying. • ECG changes: There are specific changes in the heart’s activity that can tell doctors about your heart health. When they are present during stress, it may mean your heart muscle isn’t getting enough...

Ejection fraction is a measurement doctors use to calculate the percentage of blood that leaves your heart each time it contracts. As your heart beats, it pumps (ejects) blood into your body from the two lower muscular chambers, known as the left and right ventricles. Between beats, when your heart relaxes, the two ventricles fill up with blood. However, it takes more than a single contraction to pump all the blood out of a ventricle. Ejection fraction is a test your doctor can use to determine the percentage of blood that leaves the left ventricle each time your heart beats, and to understand how well your heart works. Ejection fraction can help diagnose heart failure. Generally, your left ventricle is the one measured for ejection fraction. It does the heavy lifting in your body, pumping blood to almost all your major organs. However, current An accurate left ventricle ejection fraction (LVEF) reading can be measured through a variety of imaging techniques. The most common ejection fraction testing measures include: • Echocardiogram. An • Cardiac MRI (C-MRI). A C-MRI is an image-based test that uses a magnetic field, radio waves, and a computer to create detailed images of the inside of your heart. • Cardiac catheterization. In • Cardiac nuclear medicine scan. Trace amounts of radioactive materials are injected into your bloodstream. They’re then detected by cameras that produce images of your heart and its mechanisms. • Cardiac CT scan. This X-ray procedure can give a r...

Neonatal period Table 1. Normal limits for ECG parameters during neonatal period (Davignon et al) These reference values are the best available for the neonatal period. The intervals are 98% confidence intervals (the mean is presented in the parenthesis). Values without confidence interval are simply the 98 th percentile (i.e the upper reference limit). Age 16 years Heart rate (beats per minute) 93–155 (122) 91–158 (124) 90–166 (128) 106–182 (148) 120–179 (149) 105–185 (142) 107–168 (132) 90–151 (119) 73–137 (108) 65–133 (100) 63–129 (92) 66–120 (86) 50 – 120 Electrical axis (degrees) 58–168 (>135) 65–171 (>134) 76–168 (>133) 65–159 (110) 31–115 (75) 7–105 (60) 7–98 (54) 8–100 (55) 7–104 (55) 10–140 (66) 9–115 (61) 11–133 (58) -15 – 110 QRS duration 21–76 22–67 21–68 22–79 23–75 22–79 23–76 27–75 30–72 32–79 32–85 34–88 0.05 – 0.10 PR interval 79–160 (107) 81–139 (108) 75–137 (104) 73–138 (101) 73–130 (98) 74–145 (106) 73–156 (156) 82–148 (114) 85–161 (118) 90–164 (124) 87–171 (128) 92–175 (135) 0.12 – 0.20 Q-wave in III (mm) 0.1–5 0.1–5 0.1–5 0.1–5 0.1–5 <6.6 <6.3 <5.3 <4.2 <3.2 <2.7 <3.0 <3 R-wave in V1 (mm) 5–27 (14) 5–27 (15) 3–25 (13) 3–22 (11) 3–19 (10) 3–20 (10) 2–20 (9) 3–18 (9) 2–18 (8) 1–13 (7) 0.5–10 (6) 0.5–10 (5) 0.5 – 14 S-wave in V1 (mm) 0.5–23 (9) 0.5–21 (10) 0.5–17 (7) 0.5–12 (4) 0.5–13 (5) 0.5–17 (6) 0.5–18 (7) 1–21 (9) 2–22 (10) 3–24 (12) 3–26 (12) 3–22 (11) 0.5 – 23 R/S-ratio in V1 0.2–9.8 (2.3) 0.2–6.0 (2.0) 0.2–9.8 (2.8) 1.0–7.0 (2.9) 0.3–7.5 (2.3) 0....