ELECTROCARDIOGRAPHY RECORDING OF "P on T" WITHIN A CONTEXT OF ACUTE PULMONARY OEDEMA RECOVERED.

Keywords: Acute Pulmonary Oedema; Electrocardiographic disturbances; “R on T phenomenon”; “P on T phenomenon”; First degree AV blockade; Long QT interval.

Abstract.

One of the disorders of cardiac rhythm most feared for all cardiologists is the "R on T phenomenon". Methods. – Valuation clinical and electrocardiographic. Results. – A “P on T phenomenon”. Conclusions. - According our experience when there is an acute pulmonary oedema, is very frequent the presence of an electrocardiographic recording as this.

From long time ago is well known that, the most vulnerable period of the heart (critical phase), is the ventricular repolarisation phase: T-wave. In fact, one of the disorders of cardiac rhythm most feared for all cardiologists is the "R on T phenomenon" ¹. In the "R on T phenomenon," there are premature ventricular beats that originate in the descending branch or at the peak of T- wave.

Any event that may alter the period of myocardial vulnerability (recuperation phase, also called T-wave) can also cause lethal cardiac arrhythmias, especially the dreaded onset of sustained ventricular fibrillation and the phenomenon denominated "torsades de pointes" ^{2, 3}.

One of these potentially lethal disorders can also be produced when the P- wave (auricle depolarisation) is interconnected to descending branch of T- wave before that these branches can arrive until the baseline of the electrocardiogram. Then we could talk of "P on T phenomenon”. This phenomenon is extremely common (in our experience) when they are presents a first-degree A-V blockade and a long QT- interval in the same ECG recording.

This image of “P- wave on T- wave" is more noticeable on D2-D3-aVF leads (See illustration).

The image resembles to a spacious "m " , where both the descending branch of the T- wave as the beginning of the ascending branch of the P- wave aren't in the baseline of the electrocardiogram. In our experience, all individuals, with these electrocardiographic characteristics, had presented serious problems of ventricular fibrillation, after to suffer several episodes of pulmonary embolism (fortunately, all were recovered). Besides of exhaustive studies (Battery), all this cases have also been studied for us with genomic study and have been positives for gene of Long QT Syndrome type 2 (gene HERG, also known as KCNH2) on chromosome 7) ⁴.

Ventricular tachycardia outflow tract in left ventricle may show similar layouts. Therefore, we made differential diagnosis with this condition and we have seen that this was a different entity (Echocardiography and Electrophysiology studies)

A brief medical history.

A 55 years-old adult male. First time he has been evaluated in any Hospital. Multi-risk patients: Hypertension not controlled. Diabetes type II not controlled. Severe smoker. Habitual drinker. He comes to our emergency department by ambulance the Intensive Care Unit with: Dyspnoea severe, audible respiratory crackling, Central cyanosis. Unconsciousness. Once recovered and conscious, patient has said us to have suffered several losses of consciousness. He thought were due to abusive ingestion of alcohol.

Familial history without clinical interest.

Reflexions.

We have seen other many events as this. The typical characteristic has been a patient with an acute pulmonary oedema and with an electrocardiographic recording as in presented clinical case (after its clinical recuperation). Nevertheless, after of look on medical literature of profuse way, we have not seen none type of reference of this picture in any of them. It is clear the presence of long QT interval alongside a first degree AV blockade, and they are creating a "P on T phenomenon"

RECOMMENDED REFERENCES

1. Albert NM. Ventricular dysrhythmias in heart failure. J Cardiovasc Nurs. 2004; 19(6 Suppl):S11-26.
2. Meyerfeldt U, Schirdewan A, Wiedemann M, Schutt H, Zimmerman F, Luft FC.. The mode of onset of ventricular tachycardia. A patient-specific phenomenon. Eur Heart J. 1997; 18:1956-65.
3. Denker S, Lehmann M, Mahmud R, Gilbert C, Akhtar M. Facilitation of ventricular tachycardia induction with abrupt changes in ventricular cycle length. Am J Cardiol. 1984; 53:508-15.
4. Steve J. Compton. Robert L. Lux. Matthew R. Ramsey. Katie R. Strelich. Genetically Defined Therapy of Inherited Long-QT Syndrome Correction of Abnormal repolarization by Potassium. Circulation. 1996;94:1018-1022

Figure 1

Conventional Electrocardiogram on D1 to aVF.

Figure 2.

Complete electrocardiogram with 12 leads.