Cases reported "Arrhythmia, Sinus"

Filter by keywords:



Filtering documents. Please wait...

1/12. The nondiagnostic ECG in the chest pain patient: normal and nonspecific initial ECG presentations of acute MI.

    The 12-lead electrocardiogram (ECG) is a powerful clinical tool used in the evaluation of chest pain patients, assisting in the selection of the proper therapy. Unfortunately, the ECG is diagnostic of acute myocardial infarction (AMI) in only one-half of such patients at initial hospital evaluation. In the remaining group of patients with the nondiagnostic 12-lead electrocardiogram, the ECG may be entirely normal, show nonspecific sinus tachycardia (ST) segment-T wave abnormalities, or obvious ischemic changes. In adult chest pain patients treated in the emergency department (ED), 1% to 4% of such patients with an absolutely normal ECG had a final hospital diagnosis of AMI; furthermore, patients with nonspecific electrocardiographic abnormalities experienced AMI in 4% of cases. These findings reinforce the teaching point that the history is the most important tool used in the evaluation of chest pain patients. Furthermore, overreliance on a normal or nonspecifically abnormal ECG in a patient with a classic description of anginal chest pain is dangerous.
- - - - - - - - - -
ranking = 1
keywords = wave
(Clic here for more details about this article)

2/12. Intermittent sinus bigeminy as an expression of sinus parasystole: a case report.

    A case of sinus parasystole is reported. The diagnosis of sinus parasystole is relatively difficult because there is no difference between the basic sinus P wave and the parasystolic wave. Sinus parasystole is diagnosed according to the following electrocardiographic criteria: (1) premature P waves having contour identical to P waves of basic beats; (2) intervals between premature P waves mathematically related. In the case reported, the coupling intervals during long phases of intermittent sinus bigeminy were nearly fixed, because there was little variability in the returning cycles, making the diagnosis of sinus parasystole difficult.
- - - - - - - - - -
ranking = 5
keywords = wave
(Clic here for more details about this article)

3/12. The 12-lead electrocardiogram in anorexia nervosa: A report of 2 cases followed by a retrospective study.

    anorexia nervosa (AN) has been associated with various cardiac disorders and several electrocardiographic abnormalities, the most prominent being sudden death and prolonged QT duration and dispersion. We report 2 cases of AN with marked repolarization abnormalities, the first clearly related to electrolyte imbalance, the second without a good explanation from metabolic, electrolytic or pharmacological sources. A retrospective analysis of 47 other consecutive patients with AN showed that sinus bradycardia was the most common ECG finding, but that QT or QTc interval prolongation was not a typical feature, being present in only 1 patient. The sole variable slightly correlated with QTc duration was the serum potassium concentration. Consequently, marked repolarization changes (QT interval and/or T wave morphology) in AN should not be taken as a feature of the disease, but should call for the search of potential causes such as metabolic and electrolytic disturbances, drug effects, or a possible genetic component.
- - - - - - - - - -
ranking = 1
keywords = wave
(Clic here for more details about this article)

4/12. sleep apnea and Q-T interval prolongation--a particularly lethal combination.

    We have discovered a 20-day-old infant who possessed anatomic evidence of chronic hypoxemia with right ventricular hypertrophy and who died in hypoxic hypoxemia with a postmortem PO2 of 4 mm. Hg. Subsequently, and ECG was discovered which had been obtained at one day of age and showed Q-T interval prolongation along with T-wave alternation. We believe this case to be one of the first to substantiate the mechanism for SIDS as proposed by Schwartz, 26 with hypoxia acting synergistically with a prolonged Q-T interval causing sudden unexpected death in this infant--providing a link between cardiac and respiratory mechanisms of death.
- - - - - - - - - -
ranking = 1
keywords = wave
(Clic here for more details about this article)

5/12. Dynamic electrocardiographic changes after aborted sudden death in a patient with brugada syndrome and rate-dependent right bundle branch block.

    A 37-year-old man with brugada syndrome and dynamic changes of the ST-segment morphology observed after an episode of aborted sudden death is described. On admission, after 3 syncopal episodes during nighttime, his electrocardiogram showed right bundle branch block (RBBB) with a J-point elevation of 0.6 mV in lead V 2 . Changes observed in the following days included a diminished J-point elevation and intermittent "saddle-back" type of morphology. During a previous 2-year follow-up, intermittent, complete, acceleration-dependent RBBB was documented. Right ventricular intracavitary tracings showed an RS pattern with a broad S wave in the unipolar electrogram; the time of onset of intrinsic deflection in this electrogram was 60 milliseconds. To our knowledge, this is the first report of an intracavitary demonstration of complete RBBB in brugada syndrome.
- - - - - - - - - -
ranking = 1
keywords = wave
(Clic here for more details about this article)

6/12. Sinus parasystole.

    Sinus parasystole is the expression of a protected nondominant sinus pacemaker, which is totally independent of the dominant rhythm. Two forms of sinus parasystole are described: (1) an active form, where both the dominant and the parasystolic pacemakers are located within the sinus node and (2) a passive form, where the basic rhythm is ectopic and the sinus pacemaker is protected as a result of complete retrograde SA block. Three cases of sinus parasystole are analyzed. In the active form of the arrhythmia the parasystolic sinus P waves are identical to those of the basic sinus rhythm. The diagnosis is suggested by variably coupled premature sinus P waves occurring with mathematically related intervals. This relationship between the parasystolic intervals can not be precise whenever complicating factors such as modulation occur. The recognition of active sinus parasystole is difficult, since the parasystolic P waves do not differ from basic P waves, so that the pattern resembles that of sinus arrhythmia or sinus extrasystoles. The passive form of sinus parasystole is more easily recognized due to the clear-cut difference between the dominant ectopic atrial waves and the "parasystolic" sinus P waves, which manifest with variable coupling intervals and reflect mathematically related intervals in between.
- - - - - - - - - -
ranking = 6
keywords = wave
(Clic here for more details about this article)

7/12. Sinoventricular conduction during acute myocardial ischemia.

    A case with sinoventricular conduction and sinus bradycardia during unstable angina pectoris is presented. Although His bundle electrogram showed atrial and His bundle deflection no P waves could be observed in any surface leads even when effective high right atrial pacing was performed. It may be assumed that the electric or sinus impulses are conducted over the specialized atrial tracts while atrial muscle is in a refractory state due to myocardial ischemia.
- - - - - - - - - -
ranking = 1
keywords = wave
(Clic here for more details about this article)

8/12. Changing P waves after mitral valve replacement.

    A 55-year-old man is convalescing from mitral valve replacement five days earlier. He had severe calcific mitral stenosis and moderately severe hypertension, with repeated attacks of acute pulmonary edema. He had always been in normal sinus rhythm, except for a single episode of atrial fibrillation associated with one of his episodes of acute pulmonary edema. He had been taking digoxin (0.25 mg daily) but this was stopped the day before the operation. The cardiac rhythm has been mostly regular since the operation, but occasional irregularities have been noted. An ECG on the fifth postoperative day is shown.
- - - - - - - - - -
ranking = 4
keywords = wave
(Clic here for more details about this article)

9/12. Alternating sinus rhythm and intermittent sinoatrial block induced by propranolol.

    Alternating sinus rhythm and intermittent sinoatrial (S-A) block was observed in a 57-year-old woman, under treatment for angina with 80 mg propranolol daily. The electrocardiogram showed alternation of long and short P-P intervals and occasional pauses. These pauses were always preceded by the short P-P intervals and were usually followed by one or two P-P intervals of 0.92-0.95 s representing the basic sinus cycle. Following these basic sinus cycles, alternating rhythm started with the longer P-P interval. The long P-P intervals ranged between 1.04-1.12 s and the short P-P intervals between 0.80-0.84 s, respectively. The duration of the pauses were equal or almost equal to one short plus one long P-P interval or to twice the basic sinus cycle. In one recording a short period of regular sinus rhythm with intermittent 2/1 S-A block was observed. This short period of sinus rhythm was interrupted by sudden prolongation of the P-P interval starting the alternative rhythm. There were small changes in the shape of the P waves and P-R intervals. S-A conduction through two pathways, the first with 2/1 block the second having 0.12-0.14 s longer conduction time and with occasional 2/1 block was proposed for the explanation of the alternating P-P interval and other electrocardiographic features seen. atropine 1 mg given intravenously resulted in shortening of all P-P intervals without changing the rhythm. The abnormal rhythm disappeared with the withdrawal of propranolol and when the drug was restarted a 2/1 S-A block was seen. This was accepted as evidence for propranolol being the cause of this conduction disorder.
- - - - - - - - - -
ranking = 1
keywords = wave
(Clic here for more details about this article)

10/12. Incomplete interpolation caused by sinoatrial pacemaker shift. A report of two cases.

    Shortened return cycles after premature atrial stimulation (PAS) are commonly referred to as sinoatrial entrance block and exit delay at the sinoatrial junction or sinus-node reentries. In the 2 reported cases PAS at critical coupling intervals was followed by shortened return cycles characterized by a changed high right electrogram (and surface P waves in 1 case) and a normal sequence of atrial activation with unaltered intraatrial conduction. These changes lasted for some beats and a concomitant shorter or longer atrial cycle length was observed. Electrophysiological events furnish indirect evidence of sinoatrial pacemaker shift as a cause of incomplete interpolation in man.
- - - - - - - - - -
ranking = 1
keywords = wave
(Clic here for more details about this article)
| Next ->


Leave a message about 'Arrhythmia, Sinus'


We do not evaluate or guarantee the accuracy of any content in this site. Click here for the full disclaimer.