CME INDIA Case Presentation by Prof. Dr. M. Chenniappan, MD, DM, FACC, FACP, FRCP. Consultant Cardiologist, Ramakrishna Nursing Home, National Professor of IMA – CGP. Director of Medical Education, Apollo Speciality Hospital, Thiruchirappalli (Tamil Nadu, India).
CME INDIA Case Study
“Clock shows 30 seconds past six thirty”
This is the ECG of 60-year-old Male Smoker.
What is the diagnosis?
- This ECG shows very small P, QRS, T complexes in Lead I. This usually happens in patients with COPD.
Why is this clue?
- The clue sixty seconds past six thirty sign is given because, p axis, QRS axis and T axis all in the same line towards lead avF. Because all the three complexes’ axis is going towards aVF, LI becomes equiphasic zone of these complexes and because of this, P QRS and T waves are very small in LI. If you imagine axis diagnosis as a clock, when all waves axis is towards avF, it is like the time of sixty seconds past six thirty in the clock. That is why this clue is given
What are the other names of this sign?
- Other names for this ECG are “Schamroth sign” or “Lead I sign.
What is the practical implication?
- The practical implication is that whenever ECG in a patient with COPD shows Right Axis deviation and RA, RV involvement indicates bad prognosis due to associated pulmonary hypertension and corpulmonale. This sign indicates vertical heart due to compressed heart due hyperinflated lungs.
This sign indicates vertical heart due to compressed heart due hyperinflated lungs.
“ECG can be Poor man’s ECHO”
This is the ECG of 29-year-old female presenting with breathlessness.
What are all the ECG findings?
- The ‘p’ wave is inverted in L III and avF due to left axis deviation of P wave and not due to Junctional Rhythm or Low Atrial Rhythm because P wave in L II is upright. If you look at the ‘p’ wave in L I and avL it is bifid and wide and with predominant negative component in V1 one should suspect left atrial enlargement.
How can ECG be poor man’s ECHO?
- ECG as Poor man’s ECHO: In addition, left atrial enlargement described above, patient qR in V1. The tall R wave in V1 with Right Axis deviation in limb leads is suggestive of Right Ventricular Enlargement (RVE). So, the presence of Left Atrial Enlargement (LAE) and RVE in a 29-year-old female is suggestive of severe Mitral Stenosis (MS)with Pulmonary Hypertension. The qR pattern in V1 is suggestive of severe Right Atrial Enlargement (RAE) because in severe RAE, the V1 will face RA and show qR pattern. In the presence of pulmonary hypertension (PHT), severe RAE is suggestive of significant tricuspid regurgitation (TR). So, if carefully seen, ECG has given almost all findings shown in ECHO – that is why it is poor man’s Echo.
What are practical implications?
- The ECG itself has indicated severe MS, Severe PHT, Severe TR and it definitely needs either non-surgical (Balloon Mitral Valvotomy) or Surgical intervention. (MVR)
This the stress ECG of 68 years old man who c/o palpitations during 1st stage and exercise was stopped. This ECG is 1 minute into recovery.
What will you not do except?
- IV adenosine
- Early CAG
- Start beta blockers, antiplatelets and statins
- Ask a question
Ask the question where is the raw data?
- The post stress recovery ECG shows sinus tachycardia with infero lateral horizontal ST depression. There is ST elevation in avR. There are regular p waves in ST segment which are non-conducted. The overall interpretation of this ECG is likely to be significantly positive stress test, likely to be Triple Vessel Disease with Left Main Coronary Artery critical occlusion. In addition, there seems to be paroxysmal Atrial Tachycardia with 2:1 ventricular response. But please look at the top of the ECG which says “Linked Medians” which indicates that leads L I to V6 (all 12 leads) are generated by the computer from the real raw ECG data of the patient.
- This type of linked medians is generated by the computer to give clean ECG complexes without muscle or somatic tremor artefacts as well as baseline wanderings which usually happen in real raw ECG data from the patient, who is exercising. It is important to realize that these linked medians which are generated by the computer are reliable only when the patient’s real raw ecg data of the exercising patient is good and regular. If the patient’s raw ECG data is corrupted due to muscle artefact or baseline wonderings due to inadequate preparation of skin and poor contact of electrodes with the skin, the linked medians are not reliable, as the computer tends to generate abnormal ECG complexes from the corrupted real raw data. This is what happened in this ECG.
- The real raw data of ECG is seen in L II rhythm strip at the bottom (Fig. 4) which shows sinus tachycardia with fast upsloping ST depression and frequent ventricular ectopics (VPDs). If you compare this L II with linked medians of L II above, both look completely different. The presence of frequent VPDs had confused the computer and computer is generating a falsely abnormal ECG with ST depression and paroxysmal atrial tachycardia. But really patient had none of these changes according to raw data. The palpitation was due to VPDs rather than due to “Pseudo Atrial Tachycardia.”
Fig.4 CG with raw data in rhythm strip at bottom; compare it LII in the 12 lead ecg which is linked median.
- As the linked medians in this ECG, are misleading as strongly positive stress test with Atrial Tachycardia, the linked medians are lying because of the raw data in L II rhythm strip at the bottom shows only fast upsloping ST depression and Ventricular Ectopics. Because of this the clue of “Linked Lie” is given.
- If one believes the linked median in this ECG, the patient will be treated wrongly with anti-arrhythmic drugs as well as will be subjected to unnecessary intervention such as early Coronary Angiogram (CAG). This will result in excessive anxiety, dangers of antiarrhythmic drugs as well as excessive expenditure of CAG. As far as real raw data, the patient does not require any of above drugs or investigations. So the lesson in reading the stress ECG recordings is that one should only look at raw data and not the computer synthesised linked medians. To get the clear raw data without artefacts, good skin preparation and proper application of electrodes are needed.
“Watch the watch”
This ECG of a 53-year-old Diabetic male complaints of chest pain.
ECG shows sinus tachycardia, Tall R wave in V1, Left atrial abnormality and normal axis. There is also prominent septal q in V5, V6 as well as L1 and avL. There are many causes for Tall R wave in V1 like RVH, RBBB, Dextrocardia, Type A WPW pattern, Hypertrophic Cardiomyopathy, Duchenne Muscular Dystrophy, etc. In our patient the cause of tall R wave is likely to be due to counter clockwise rotation. This is unlikely to be asymmetrical Septal Hypertrophy because there are no deep narrow septal q waves in V5, V6. Counter clockwise rotation is diagnosed if equiphasic zone in chest leads shifted to right. In our ECG, equiphasic zone is in V1 and V2.
Description about clockwise and counter clockwise rotation.
- Clockwise and counter clockwise rotation refers to a change in the electrical activity in a horizontal plane through the heart.
- Imagine the observer standing at the feet of the patient who is in bed.
- If the electrical activity of the heart has turned more to the right side of the patient this is called counter clockwise rotation.
- If the electrical activity of the heart has turned more to the left side of the patient this is called clockwise rotation.
- Clockwise and counter clockwise rotation can be assessed only in the chest-leads (V1 – V6).
- Normally the R wave amplitude increases from V1 to V5. Around V3 or V4 the R waves become larger than the S waves and this is called the ‘transitional zone’.
- If the transition occurs at or before V2, this is called counter clockwise rotation. — If the transition occurs after V4, this is called clockwise rotation. (Fig 6)
Intraventricular conduction abnormalities secondary to myocardial degeneration
- Right ventricular heart disease.
Shift of the septum to the left
- Dilated cardiomyopathy.
Shift of the whole heart
- Pulmonary emphysema.
- Vertical heart (usually thin and tall persons).
Causes of counter clockwise rotation
Electrical shift to the right
- Right ventricular hypertrophy
- WPW Syndrome
- Posterior myocardial infarction
- Left post. fascicular block
Shift of the septum to the right
- Hypertrophic cardiomyopathy.
- The deep terminal negative component of P in V1 is suggestive of left atrial abnormality and so left ventricular dysfunction must be excluded.
The clue is about the Counter “clock “wise rotation as the cause of Tall R wave in V1. Observing or watching the watch (clock) will give the diagnosis.
Counter clockwise rotation, the most prevalent QRS transition zone pattern, demonstrated the lowest risk of CVD and mortality, whereas clockwise rotation was associated with the highest risk of heart failure and non‐CVD mortality. These results have implications on how to interpret QRS transition zone rotation when ECG was recorded.
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