Original Articles

By Prof. Francisco R Breijo-Marquez
Corresponding Author Prof. Francisco R Breijo-Marquez
Cardiology. East Boston Hospital. School of Medicine, 02136 - United States of America 02136
Submitting Author Prof. Francisco R Breijo-Marquez

Short PQ-interval; Short QT-interval. Syncope; Tachyarrhythmias; Electrical cardiac disorders.

Breijo-Marquez FR. Accelerated atrioventricular stimulation with an early and shortened ventricular repolarization in the same individual. WebmedCentral CARDIOLOGY 2014;5(3):WMC004589
doi: 10.9754/journal.wmc.2014.004589

This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submitted on: 11 Mar 2014 12:38:29 PM GMT
Published on: 11 Mar 2014 12:41:20 PM GMT



Raise awareness all cardiologists that this kind of problems in the heart's electrical system exist and must be carefully assessed.


We will present a clinical condition characterized by the presence of a short PQ interval and a short QT interval in the same individual.

The Short PQ syndrome is characterized by a duration < 0, 12 seconds. We know its variants.

The short QT syndrome has been described recently (2000-03). We speak of short QT if its length is < 0.350 second.

Both are known individually. However, there is an electrocardiographic pattern little known until today:

A pattern with short "PQ-interval and QT-interval” in the same ECG tracing.


The QT interval is a reflection of ventricular repolarization (1-3). Its upper normal limits are well known, and the prolongation of QT interval above these limits, it is considered an independent risk factor for sudden death. There are many information on syndromes congenital and acquired long QT and its relationship to mortality (3-4). By contrasting, little is known about the causes and prognostic value of Short QT interval (5-7). It is difficult to know the index of this syndrome. Although only a few cases have been reported, the rate may be underestimated, because, until now, little attention has been focused on the diagnosis of short QT electrocardiogram (6-7). Patients with short QT syndrome have a wide clinical spectrum including palpitations, tachycardia, episodes of syncope and sudden cardiac death, and a family history of it through several generations. (5-6-7).

We have demonstrated the presence of this pattern in several persons with symptoms of childhood convulsions - diagnosed as epilepsy despite not display any epileptic focus on studies of electroencephalography (EEF) – as well as nocturnal tachycardia crisis and syncope events related to repetitive physical effort (8-9).

Electrical cardiac systole comprises:

Atrial depolarization (P wave). PQ- interval. Ventricular depolarization (QRS complex). ST Segment. Ventricular repolarization (T wave).

In many cases, the determination of the end of the T wave is very difficult to calculate.

In Medicine and specifically in Cardiology, QT interval is a measure of time between the start of the Q wave and the end of the T wave (the heart's electrical cycle).

The presence of this configuration with a shortening of intervals PQ and QT represent a major cardiac instability, and consequently a high risk for serious cardiac arrhythmias (ventricular fibrillation fundamentally) and therefore also for sudden cardiac death (5).


A thorough compilation of patients with this kind of symptoms such as infantile convulsions non-responders to conventional treatments, bouts of nocturnal tachycardia with sudden character, and syncopal events related to the effort.

Exhaustive study of personal antecedents as well as your current clinical situation.

Exhaustive measurements of intervals, segments and electrocardiographic waves. Measurement technique: MioLaserTool ®, Pixruler ® & Cardiocaliper®.

By way of example, we will expose the following case

Case Report

A 37 old-years man with many nocturnal tachycardia crisis (since childhood) and three syncopal events observed and related with physical stress. In his family background, two sudden deaths were found: father died at age 55 sudden cardiac and a brother died at 22 months by sudden infant death.

He was diagnosed in his Reference Hospital (where he was transferred by emergency services) with supraventricular tachycardia to 150-170 beats per minute, with narrow QRS complexes. Severe diaphoresis, with paleness of skin and mucosa.  A severe arterial hypotension to 90/50 mm. Hg. Cardiac auscultation was in normal ranges but with a rapid rhythm. Tachypnea to 20 cycles/minute. A grade Stuporous (Glasgow 15/15).

The neurological examination was within normal ranges without focalizations. Central and peripheral pulses were palpable, symmetric and synchronous in "frecuens".

Supraventricular tachycardia disappeared by means of the administration of two doses of Adenosine i.v. in bolus, with six mgrs. each one in 1 minute (Figure 2).

A Hospital discharge was made after full stabilizing of acute process and patient was derived to your cardiologist outpatient, with the follow diagnosis:

  • A paroxysmal supraventricular tachycardia and Crisis of anxiety.

The patient was transferred to our Hospital because he had had a similar event as the exposed, after the first visit with his outpatient cardiologist.

There, the patient was adequately assessed with electrocardiogram, echocardiogram, blood levels of ions and cardiac markers as well as electro-physiological study (EEF). He was negative for high levels of Troponin (I-T), CK, CPK and however he was positive for a low levels of lithium ion (< 0.01 mcg)

In a detailed assessment on ECG, we can note that the patient has a short PQ- interval with a short QTc in the same ECG tracing (Bazett and Fridericia formulas) with a risk of sudden cardiac death, according to the Schwartz scale of 4.5 points:  High risk for sudden cardiac death.

At first glance, the ECG tracing interpretation suggests a syndrome Lown - Ganong - Levine, but  in a more detailed  checkup we see as the QTc interval in the LGL syndrome is normal while in this patient, the QTc interval is short (< 0.350 s). We have therefore two possibilities: an unknown variant of LGL Syndrome or a new electrical cardiac disease.


Both PQ and QT intervals are short.

PQ- interval: 0.10 - 0.11 seconds. RR interval:  around 0.862- 0.900 seconds.  QT- Interval:  around 0.322-0.330 seconds. Bazett formula: around 0.339-0.343 seconds.  Fridericia formula: around 0.330-.337 seconds.


An electrical heart feature that has not been described at present with decreased duration of electrical cardiac systole: PQ and QTc-intervals are short (for some authors, it has been called "Breijo Pattern").


To reduce its more than likely underdiagnosis, all doctors should measure segments, intervals and waves electrocardiographic in all ECG tracings. A new electrical cardiac disease or pattern may have been discovered.

This described patient is not the only one in our collection, but just one example. Raising awareness among doctors of the existence thereof is prescriptive. Avoid preventable sudden deaths is the duty of all doctor, therefore knowledge of this characteristic electrocardiogram alongside clinical features patient should be a commandment.


1. Cowan, JC, Yusoff, K, Moore, M. et al. Importance of lead selection in QT interval measurement. Am J Cardiol 1988;62,83-87.
2. Zabel, M, Franz, MR, Klingenheben, T. et al. Rate-dependence of QT dispersion and the QT interval: comparison of atrial pacing and exercise testing. J Am Coll Cardiol. 2000;36,1654-1658
3. Glancy, JM, Garratt, CJ, Woods, KL. et al. Three-lead measurement of QTc dispersion. J Cardiovasc Electrophysiol. 1995;6,987-992
4. Behrens, S, Li, C, Knollmann, BC. et al. Dispersion of ventricular repolarization in the voltage domain. Pacing Clin Electrophysiol. 1998;21,100-107
5. DeBruyne, MC, Hoes, AW, Kors, JA. et al. QTc dispersion predicts cardiac mortality in the elderly: the Rotterdam Study. Circulation. 1998; 97,467-472.
6. Gussak I, Brugada P, Brugada J. et al. Idiopathic short QT interval: a new clinical syndrome? Cardiology. 2000; 94: 99–102.
7. Gaita F, Giustetto C, Bianchi F. et al. Short QT syndrome: a familial cause of sudden death. Circulation. 2003; 108: 965–970.
8. Breijo-Marquez FR. Decrease of electrical cardiac systole. Int. J. Cardiol. 2008; 126: 2, 23 e36–e38.
9. Breijo-Marquez FR. Pardo Rios M. Variability and Diversity of the electrical cardiac sístole. BMJ. 2009: bcr06.2008.0284.

Source(s) of Funding


Competing Interests


5 reviews posted so far

I think this is necessary to know.
Posted by Prof. Francisco R Breijo-Marquez on 06 Apr 2014 03:05:57 PM GMT Reviewed by Interested Peers

Cardiovascular Physician
Posted by Dr. Nassir A Azimi on 27 Mar 2014 09:26:18 PM GMT Reviewed by WMC Editors

Thank so much for your wwords, Dr Azimi.

... View more
Responded by Prof. Francisco R Breijo-Marquez on 31 Mar 2014 09:44:39 AM GMT

1 comment posted so far

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Comments by Dr. Valenti Posted by Prof. Francisco R Breijo-Marquez on 31 Jul 2014 06:35:11 AM GMT


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