Left Atrial Overload Research Articles

Spatial velocity electrocardiogram of the P wave in atrial overload.

The SVECG was recorded in grand total of 119 cases with mitral stenosis in 35 cases, atrial septal defect in 51 cases, tetralogy of Fallot in 22 cases and pulmonary stenosis in 11 cases, and the correlation with hemodynamic data in 107 cases and operation findings in 78 cases was investigated. The atrial SVECG in atrial overloadings is composed of 3 types as seen in normal subjects: two-peaked, three-peaked and four-peaked patterns. In the atrial SVECG of left atrial overloading, the first peak was considered to reflect the activation of right atrium and did not increase significantly in amplitude compared with normal subjects. The spatial velocity and time interval of the third and/or fourth peaks, which were considered to reflect mainly the depolarization of the left atrium, increased significantly. The P3/P1 and P4/P1 ratios had positive correlates with the mitral valvular area ascertained at surgical operation. The atrial SVECG represents the right atrial overloading as a two-peaked pattern. Its incidence was high as in ASD group (65%) as in TF (73%) and PS (73%) groups in spite of significantly lower right ventricular systolic pressure in ASD group than in TF and PS groups (P<0.01 and P<0.01 respectively). In TF group the right ventricular systolic pressure was significantly higher in the two-peaked subgroup than in the three-peaked one (P<0.05).

Serial observations on left ventricular dysfunction in acute myocardial infarction. I. Gallop sounds, ventricular asynergy and radiological signs.

Abstract. The occurrence and significance of various signs of left heart pump failure have been studied serially in 50 patients with acute myocardial infarction (AMI) 1, 2, 3, 5, 10, 15, and 20 days after the onset of symptoms. The clinical severity of AMI, the findings on cardiac palpation and auscultation, the electro‐, phono‐, and kinetocardiographic findings and the radiological signs of left ventricular failure were evaluated. Evidence of left ventricular dysfunction was observed in all patients: atrial gallop in 100% (audible in 82%), a high a wave kinetocardiographically in 92%, ventricular gallop in 90% (audible in 80%), papillary muscle dysfunction in 58%, ventricular asynergy kinetocardiographically in 100% (a palpable paradoxical pulsation in 86%), pulmonary rales in 70%, pulmonary vascular congestion in serial X‐rays in 98%, and enlargement of the heart in 42%. These signs developed during the first days, also in patients with normal‐sized hearts, and persisted in the majority. Because of their high prevalence, auscultatory and phonocardiographic signs of myocardial dysfunction and, similarly, ventricular asynergy as demonstrated by palpation and kinetocardiography, if assessed cross‐sectionally, were not useful in assessing the hemodynamic severity of AMI or its prognosis. However, serial studies indicated that changes in the clinical course of AMI are accompanied by parallel changes in the clinical signs of left ventricular dysfunction. Radiological signs of pulmonary vascular congestion and electrocardiographic signs of left atrial overloading are valuable in the assessment of the clinical severity and course of AMI.

Value of serial P wave changes in indicating left heart failure in myocardial infarction.

In order to evaluate ventricular failure in acute myocardial infarction, electrocardiographic left atrial overloading was correlated to several simultaneous clinical and radiological signs of left ventricular dysfunction in 200 consecutive patients. Analyses were made at three time periods after infarction. Left atrial overloading, measured by P terminal force, was significantly associated with the signs of left ventricular dysfunction, though in this unselected series of infarctions the prevalence of abnormal values was not high (46%). This finding is to be considered rather as a contributory sign than as a diagnostic one in the entire clinical picture. In an individual patient, however, conspicuous serial changes are helpful in indicating the direction of course of the haemodynamic disorder. The prognostic value of the P terminal force was found to be significant.

Electrocardiography in Acute Papillary Muscle Dysfunction and Infarction: A Clinicopathologic Study

The electrocardiograms of 30 patients dying of acute myocardial infarction were analyzed for changes held relevant to recognition of papillary muscle dysfunction and infarction. The findings before and after acquisition of acute papillary muscle dysfunction in 19 patients were compared with those in 11 patients without mitral systolic murmur and related to the papillary muscle necrosis found at subsequent autopsy. While mitral systolic murmur observed at auscultation correlated significantly with extensive infarction of the papillary muscles, the electrocardiographic features, including the ST segment and TU-U complex, had no value for a selective recognition of papillary muscle dysfunction or infarction in association with acute cardiac infarction. The location but not the size of the infarct was important in determining papillary muscle insufficiency: this was more common with inferior or posterior location of the infarction. Pump failure of the left ventricle, further compromised by acute mitral regurgitant flow, was sensitively and rapidly reflected by electrocardiographic changes of left atrial overloading.

Serial P wave changes in acute myocardial infarction

Tall, peaked P waves of normal duration were recorded in Lead 2 of the ECG in 24 patients during the course of acute myocardial infarction and were observed to be transient in 21 of these. No patient had evidence of valvular heart disease, pulmonary emboli, or other pulmonary pathology. Fourteen patients had manifestations of left-sided congestive heart failure during the time of greatest P-wave abnormality. Twelve patients had concomitant abnormal posterior rotation of the P-wave vector, indicative of left atrial overloading. The possible factors in the genesis of these P-wave alterations are discussed. The pattern of P pulmonale may occur during the course of an acute myocardial infarction in the absence of demonstrable pulmonary emboli or other pulmonary pathology.

The electrocardiographic recognition of left atrial enlargement in childhood

The P wave of the scalar electrocardiogram has been evaluated in a group of normal infants and children, and in a group of children with left atrial volume overload due either to ventricular septal defect or mitral regurgitation. In the normal group the P wave in Lead V 1 was frequently diphasic, with the terminal negative deflection smaller than the initial positive component, however. With left atrial overload, the negative P-V 1 deflection becomes more prominent, and the P wave in Lead V 2 may also become diphasic. Amplitude and duration of the terminal negative P-V 1 have been measured, and their product, the “terminal P-V 1 index”, obtained. In the absence of left atrial overload, the terminal P-V 1 index is ordinarily not greater than 0.015 mm. sec., the 90th percentile, or one half of a small square on ECG paper. Patients with left atrial overload have a significantly greater terminal P-V 1 index and can thus be identified. Abnormal negativity of the P-V 1 deflection, as expressed in the terminal P-V 1 index, does not occur with mild left atrial overload, but is consistently present with more significant degrees of overload. In a group of patients with prominent left atrial overload, the terminal P-V 1 index was abnormal in 92 per cent. The terminal P-V 1 index is compared with other electrocardiographic measures of left atrial abnormality. Prolonged P duration is more sensitive an indicator than terminal P-V 1 index, but is frequently not present in patients with prominent overload. Abnormal P morphology is confined to patients with more severe left atrial overload, but identifies less than half the number of these who are identified by an abnormal terminal P-V 1 index. An increased P P -R segment ratio is often a nonspecific finding. Unusual negativity of the P wave in Lead V 1, as indicated by an abnormal terminal P-V 1 index, correlates quite well with roentgenographic evidence of increased left atrial size. To date, abnormal negativity of the P wave in Lead V 1 is the sole electrocardiographic measure of left atrial enlargement which has this advantage.

A CASE OF VENTRICULAR PAROXYSMAL TACHYCARDIA WITH ABNORMAL P WAVES.

A case of ventricular paroxysmal tachycardia with abnormal P waves is presented. As regard to the identification of P waves during paroxysm, the high gain electrocardiogram is more useful than the conventional electrocardiogram. The P wave abnormalities are considered to show left atrial overloading. The conduction disturbance in the atria may be the precipitating factor for the ventricular tachycardia.

Electrocardiographic and Phonocardiographic Studies in Hypertension

The Pwave in hypertension was studied comparing with that in normal and mitral stenosis.(1) In various findings of the Pwave, there were significant differences between normal and pathological conditions. Hypertensive cases had inter-mediate changes compared with the other two groups, and these changes were intensified by the elevation in the diastolic blood pressure level.(2) From the results obtained in these comparison studies, we proposed the 7 electrocardiographic criteria to assess the changes in the Pwave in both hypertensive and mitral stenosis. In hypertensive cases, the incidence of each criterion was increased according to the elevation in the diastolic blood pressure level. Special attention was given to some criteria, namely relative left axis deviation of the Pwave, which was characteristic to mitral stenosis and mild hypertension, and the finding that the amplitude of the Pwave in lead V6 was higher than that in V5, which indicated the more definite sign of the left atrial overloading and often seen in mitral stenosis and severe hypertension.(3) The grade of Pwave change gave us the more distinctive differentia-tion of the Pwave between normal and mitral stenosis. In hypertension, this grade was increased with the elevation in the diastolic blood pressure level, and in severe cases, the grade of Pwave change became similar to that seen in mitral stenosis.(4) On the bases of the observations in the follow-up cases as well as above-mentioned results, we suggested that the change in the Pwave in hypertension was a reflection of the left atrial overloading possibly resulted from the left ventricular one.

Auricular overloadings: Electrocardiographic analysis of 193 cases

The authors studied the auriculograms of 193 patients presenting mitral lesions (41 cases), congenital cardiac malformations (100 cases), and pulmonary disease (52 cases). In the great majority of the cases hemodynamic correlations were established and in 20 patients the vectorcardiogram was analyzed. The chief characteristics of the P wave and the P vector in left, right, and combined atrial overloading are stressed. The following conclusions are drawn: 1. (1) The most important findings for left atrial overloading are a marked backward orientation of the P vector, appearance of notching and increase in the duration of the P waves in the limb and left precordial leads. 2. (2) There seems to exist a correlation between the duration of the P waves and the degree of left atrial dilatation. 3. (3) P waves with normal duration may exist in the presence of hypcrtrophied but not significantly dilated left auricles. 4. (4) A tendency of the AP to deviate to the right in patients with mitral lesions was found whenever the right auricular pressures were elevated. 5. (5) In all cases of significant right auricular systolic overloading (systolic pressure above 10 mm Hg) in our series of congenital heart diseases, the amplitude of the P waves was above 2 mm either in the limb or precordial leads. 6. (6) Arterial oxygen desaturation tends to increase the amplitude of the P waves. Patients with both elevated right atrial pressures and arterial desaturation presented the highest P waves in this study. 7. (7) Slight degrees of right atrial overloading, particularly in patients with interatrial septal defect, were detected in many cases by the presence of peaked P waves of normal amplitude, mostly in V 1 and V 2. 8. (8) The interpretation of the ventricular complex adds important data in the diagnosis of right atrial overloading. 9. (9) Pulmonary emphysema and arterial desaturation as a consequence of disturbance in the mechanism of hematosis, in patients with chronic disease of the lungs, produce marked changes in the P waves and the P vector. The P waves become tall and peaked and the AP is deviated rightward and downward. 10. (10) In the presence of pulmonary emphysema with arterial desaturation, it is very difficult to decide by the auriculogram whether there also exists right auricular overloading. 11. (11) The existence of combined auricular overloading may be suspected from the ECG for two reasons: (a) the presence of morphologic signs compatible with overloading of both atria; (b) the existence of morphologic signs of left atrial overloading associated with a tendency of the AP to deviate to the right. 12. (12) Vectorcardiogram: P loops with leftward and backward orientation, increased in width, and sometimes showing eight-shaped figures are very suggestive of left atrial overloading. P loops with normal width, increased magnitude and a forward orientation are diagnostic of right atrial overloading.