V tach is identified by: wide QRS complexes (>.12 seconds), rate faster than 100 bpm. In MONOMORPHIC V tach, all QRS complexes look alike. There are other mechanisms of wide-complex tachycardia, but they can be difficult to differentiate from a single rhythm strip. All WCT should be treated as V tach until proven otherwise.
These two ECGs are from a 77-year-old woman who was complaining of palpitations and mild shortness of breath. She stated a history of atrial fibrillation. She was alert, with a systolic BP over 120. At the hospital, she was found to have cardiomyopathy, resulting in global hypokinesis. She also had significant coronary artery narrowing in her left main, left anterior descending, and circumflex, which were treated with coronary artery bypass graft surgery.
These two strips are from one patient who was electrically cardioverted twice in a few minutes. The original reason for the cardioversion was Torsades de Pointes, a type of polymorphic ventricular tachycardia associated with a long QT interval. For more information about TDP, go to this LINK. It is a bit difficult to comment on the patient's post-cardioversion rhythm, because so little of it is shown. It appears to be sinus, with a wide QRS.
An example of ventricular tachycardia in Lead II. This patient's rate is about 190/min. V Tach will have the following criteria: Rate greater than 100/min, QRS duration greater than .12 sec. (120 ms), and no P wave associated with the QRS.
It can be difficult to distinguish V Tach from other wide-complex tachycardias without a 12-lead ECG, but all wide-complex tachycardias should be treated as V Tach until proven otherwise, as V Tach is a potentially lethal dysrhythmia. V Tach can cause a severe reduction in cardiac output which can lead to V Fib and death.
This ECG shows a wide-complex tachycardia with a rate of 137/minute. No patient information is available other than what is on the ECG. Here, we will comment for the BASIC LEVEL learner, and allow the ECG Gurus out there to add INTERMEDIATE and ADVANCED level comments.
Torsades de pointes, or polymorphic ventricular tachycardia, is a ventricular tachycardia precipitated by and associated with long QT Syndrome. Long QT Syndrome can be congenital or acquired. Torsades is life-threatening, and can be made worse by many drugs, including some of the drugs used to treat VT. The rate is usually 150 - 250 / min. and the appearance is of a wide-complex tachycardia with QRS morphology changes.
This is a good example of ventricular tachycardia with PRECORDIAL CONCORDANCE. The QRS complexes in the chest, or precordial, leads all point downward. When the precordial leads are all negative or all positive in a wide-complex tachycardia, there is virtually a 100% chance that the WCT is ventricular tachycardia. This ECG shows many characteristics of VT, including the extreme "backwards" axis: aVR is positive and II, III, and aVF are negative. Lead I is almost equiphasic. Also, the lack of a clear BBB pattern and a negative V6 are strongly suggest
A 66 year old man is complaining of palpitations and chest pain which radiated to his left arm and neck, which lasted 20 minutes, then went away. Paramedics found him in V Tach. His BP was 120/80 and his pulse 120/min. He converted to a narrow-complex rhythm while being given amiodarone, but became nauseated. He returned to V Tach, and his symptoms disappeared. This patient had an implanted defibrillator, which never went off. How do we know this is V Tach?
This ECG was presented earlier this week as an example of SVT with LBBB aberrancy, which was ultimately converted with one dose of adenosine in the Emergency Department. It is the most shared and commented on ECG yet to appear on the Guru. The diagnosis given was the one accepted by the medical staff who cared for the patient, who was a man in his 30's who presented to the Emergency Department complaining of a rapid heart rate. He was ambulatory with stable vital signs, in spite of the tachycardia.
This is an interesting ECG for showing students AV sequential pacing and also ventricular tachycardia. The unusual thing about this ECG is that the V Tach starts at the time the machine begins recording the precordial leads. This particular ECG machine shows a slight "gap" at the lead change, so we don't see the actual start of the V Tach. Both rhythms have wide QRS complexes.
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