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Hyperventilation-induced T Wave Inversion

Hyperventilation induced T wave inversion

Normal T Wave
Hyperventilation
Inverted T Waves and Hyperventilation
Differential Diagnosis

Normal T Wave

ECG normal positive T wave

Concordant T Wave

ECG abnormal disconcordance T wave, positive QRS, negative inverted T wave

Disconcordant T Wave

The T wave is the most variable wave on the ECG

It represents ventricular repolarization
It is low and wide

It is concordant (has the same polarity as the QRS)

Positive QRS - positive T wave
Negative QRS - negative T wave

It is positive (I, II, V3-V6)

It may be isolated negative (III, aVL)

It is negative (aVR)
Amplitude

In limb leads, < 5mm
In chest leads, < 15mm

For ECG diagnosis, the dynamics of the T wave is important

If the T wave remains the same - it often does not indicate a serious condition
If the T wave changes - it often indicates a serious condition (ischemia)

Hyperventilation

Hyperventilation, overbreathing, Hyperventilation syndrome, respiratory alkalosis

During hyperventilation, more carbon dioxide is exhaled

than is produced in the body

Respiratory alkalosis occurs (pH increases in the blood)

There is a change in mineral concentration

Ionized calcium decreases

Muscular excitability increases and tetanic contractions occur

Obstetric hand sign – Trousseau's sign
Carpopedal spasms – Chvostek's sign

An increase in pH by 0.1 causes a decrease in potassium by approximately 0.5mmol/l

Hyperventilation thus causes hypokalemia, which leads to EKG changes:

If serious conditions are excluded (e.g., pulmonary embolism)

then treatment of hyperventilation includes:

Calming the patient
Breathing into a plastic bag (the patient rebreathes carbon dioxide)

Inverted T Waves and Hyperventilation

Hyperventilation T wave inversion

Hyperventilation causes (temporary changes) on an EKG:

Inverted T waves

Occur mainly in precordial leads (V1-V6)

Prolonged QT interval

The mechanism of EKG changes is primarily transient hypokalemia

Which results from hyperventilation-induced respiratory alkalosis (Blood pH increases)
EKG changes persist for approximately 1 minute after hyperventilation

Differential Diagnosis

Ischemia in the anterior leads (V1-V6)

Ischemia also causes inverted T waves
These T waves are often associated with ST depressions

Arrhythmogenic Right Ventricular Dysplasia (ARVD)

ARVD also causes inverted T waves (V1-V3) without dynamics, but ARVD also has

Persistent Juvenile T Waves

Are inverted T waves (V1-V3) that are without dynamics
Persist from birth to adulthood

ECG T wave inversion, hyperventilation

Persistent Juvenile T Waves

It involved a 24-year-old woman who was frightened and hyperventilating, and she had no structural heart disease
Inverted T waves (V1-V5)
After calming the patient, these T waves resolved

ECG persistent juvenile T wave pattern, african-american female

Persistent Juvenile T Waves

It involved a 32-year-old African-American woman with no structural heart disease

The patient was at a routine check-up and had no subjective complaints

She had the same T waves (V1-V4) on an ECG from 7 years ago
Inverted T waves (V1-V4)

Depth < 3mm

The T waves did not change, indicating persistent juvenile T waves

These are typically found only in leads V1-V3, rarely in V4

ECG epsilon wave, inverted T wave

ECG (V1-V3) arrhythmogenic right ventricular hypertrophy, epsilon wave, inverted T wave

Arrhythmogenic Right Ventricular Dysplasia

Epsilon wave in all leads

It is characteristic of arrhythmogenic right ventricular dysplasia

Negative T waves (V1-V3), also V4-V6
Right ventricular hypertrophy and overload

R/S ratio (V1) ≥ 1
Descending ST segment and Negative T waves (V1-4) (II, III, aVF)

Heart stenosis: Circumflex branch of left coronary artery (LCx), Anterior interventricular branch of left coronary artery (LAD)

ECG ischemic inverted T waves, unstable angina pectoris, stenosis LAD, LCx

Inverted Ischemic T Waves and Unstable Angina Pectoris

The patient had unstable angina pectoris due to stenosis of the LAD and LCx

ST depression (V4-V6)
Inverted T waves (V2-V6)
After stent placement (recanalization), the T waves normalized later

For acute subendocardial ischemia, the following are characteristic

ST depressions and Inverted T waves (at least in 2 contiguous leads)

The patient had acute coronary syndrome

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers

Hyperventilation-induced T Wave Inversion

Hyperventilation induced T wave inversion

Normal T Wave
Hyperventilation
Inverted T Waves and Hyperventilation
Differential Diagnosis

Normal T Wave

The T wave is the most variable wave on the ECG

It represents ventricular repolarization
It is low and wide

It is concordant (has the same polarity as the QRS)

Positive QRS - positive T wave
Negative QRS - negative T wave

It is positive (I, II, V3-V6)

It may be isolated negative (III, aVL)

It is negative (aVR)
Amplitude

In limb leads, < 5mm
In chest leads, < 15mm

For ECG diagnosis, the dynamics of the T wave is important

If the T wave remains the same - it often does not indicate a serious condition
If the T wave changes - it often indicates a serious condition (ischemia)

ECG normal positive T wave

Concordant T Wave

ECG abnormal disconcordance T wave, positive QRS, negative inverted T wave

Disconcordant T Wave

Hyperventilation

During hyperventilation, more carbon dioxide is exhaled

than is produced in the body

Respiratory alkalosis occurs (pH increases in the blood)

There is a change in mineral concentration

Ionized calcium decreases

Muscular excitability increases and tetanic contractions occur

Obstetric hand sign – Trousseau's sign
Carpopedal spasms – Chvostek's sign

An increase in pH by 0.1 causes a decrease in potassium by approximately 0.5mmol/l

Hyperventilation thus causes hypokalemia, which leads to EKG changes:

If serious conditions are excluded (e.g., pulmonary embolism)

then treatment of hyperventilation includes:

Calming the patient
Breathing into a plastic bag (the patient rebreathes carbon dioxide)

Hyperventilation, overbreathing, Hyperventilation syndrome, respiratory alkalosis

Inverted T Waves and Hyperventilation

Hyperventilation causes (temporary changes) on an EKG:

Inverted T waves

Occur mainly in precordial leads (V1-V6)

Prolonged QT interval

The mechanism of EKG changes is primarily transient hypokalemia

Which results from hyperventilation-induced respiratory alkalosis (Blood pH increases)
EKG changes persist for approximately 1 minute after hyperventilation

Hyperventilation T wave inversion

Differential Diagnosis

Ischemia in the anterior leads (V1-V6)

Ischemia also causes inverted T waves
These T waves are often associated with ST depressions

Arrhythmogenic Right Ventricular Dysplasia (ARVD)

ARVD also causes inverted T waves (V1-V3) without dynamics, but ARVD also has

Persistent Juvenile T Waves

Are inverted T waves (V1-V3) that are without dynamics
Persist from birth to adulthood

ECG T wave inversion, hyperventilation

Persistent Juvenile T Waves

It involved a 24-year-old woman who was frightened and hyperventilating, and she had no structural heart disease
Inverted T waves (V1-V5)
After calming the patient, these T waves resolved

ECG persistent juvenile T wave pattern, african-american female

Persistent Juvenile T Waves

It involved a 32-year-old African-American woman with no structural heart disease

The patient was at a routine check-up and had no subjective complaints

She had the same T waves (V1-V4) on an ECG from 7 years ago
Inverted T waves (V1-V4)

Depth < 3mm

The T waves did not change, indicating persistent juvenile T waves

These are typically found only in leads V1-V3, rarely in V4

ECG (V1-V3) arrhythmogenic right ventricular hypertrophy, epsilon wave, inverted T wave

Arrhythmogenic Right Ventricular Dysplasia

Epsilon wave in all leads

It is characteristic of arrhythmogenic right ventricular dysplasia

Negative T waves (V1-V3), also V4-V6
Right ventricular hypertrophy and overload

R/S ratio (V1) ≥ 1
Descending ST segment and Negative T waves (V1-4) (II, III, aVF)

ECG epsilon wave, inverted T wave

ECG ischemic inverted T waves, unstable angina pectoris, stenosis LAD, LCx

Inverted Ischemic T Waves and Unstable Angina Pectoris

The patient had unstable angina pectoris due to stenosis of the LAD and LCx

ST depression (V4-V6)
Inverted T waves (V2-V6)
After stent placement (recanalization), the T waves normalized later

For acute subendocardial ischemia, the following are characteristic

ST depressions and Inverted T waves (at least in 2 contiguous leads)

The patient had acute coronary syndrome

Heart stenosis: Circumflex branch of left coronary artery (LCx), Anterior interventricular branch of left coronary artery (LAD)

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers