Letters to the Editor
Positive and negative distribution volumes To the Editor: In the February, 1975, issue of AMERICAN HEART JOURNAL, Drs. Hoffman, Rosen, and Wit discuss clinical pharmacologic considerations in the administration of antiarrhythmic agents. They state that the apparent volume of distribution is the plasma concentration divided by the dose: mg./ml. = ml. mg.
exception; the difficulty now is to obtain a normal electrocardiogram." Thus, the term applies to a rare condition with an almost continuous presence of ectopic r h y t h m frequently interrupted by brief periods of sinus rhythm. This t e r m has been used since in this connotation. The authors of the editorial "Repetitive supraventricular tachycardia in context ''2 really meant not repetitive but recurrent tachycardia. There is enough confusion in cardiac terminology already and one would hope that terms would be used in their original meaning rather than loosely.
Arthur Selzer, M.D. Division of Cardiology Presbyterian Hospital of Pacific Medical Center Buchanan and Clay Streets San ~rancisco, Calif. 94115
This would not express ml., but ml.-'. The apparent volume of distribution is actually calculated by dividing the dose by the plasma concentration1: mg. = ml. mg./ml.
William H. Jef/ery, Pharm.D. Assistant Professor of Pharmacy (Clinical) College of Pharmacy The University of New Mexico Albuquerque, N. M. 87131
REFERENCE ].
Wagner, J. G.: Biopharmaceutics and relevant pharmacokinetics, First ed., Hamilton, Ill., 1971, Drug Intelligence Publications, pp. 252-259.
REFERENCES 1. Parkinson, J., and Papp, C.: Repetitive tachycardia, Br. Heart J. 9:241, 1941. 2. Castellanos, A., Jr., and Myerburg, R. J.: Repetitive supraventricular tachycardias in context, AM. HEART J. 90:131, 1975.
Criteria for the LGL syndrome To the Editor:
Reply To the Editor: We wish to thank Dr. Jeffery for bringing to our attention this typographical error on our part. As he correctly points
out, AVD -
mg. mg,/ml.
- ml.
Brian F. Hoffman, M.D. Michael R. Rosen, M.D. Andrew L. Wit, Ph.D. Dept. of Pharmacology College of Physicians and Surgeons Columbia University 630 W. 168th St. New York, N. Y. 10032
Repetitive supraventricular tachycardia out of context To the Editor: The term "repetitive tachycardia" was coined by Parkinson and Papp I with a specific connotation and precise definition "recurrent paroxysms are the rule and normal rhythm is the
American Heart Journal
In your Editorial article for August last year (AM. HEART J. 90:131, 1975) Castellanos and Myerburg I argue for new criteria for the LGL syndrome. I do agree with them, but for different reasons: In the original article Lown, Ganong, and Levine~ describe "the syndrome of short P-R interval, normal QRS complex and paroxysmal rapid heart action. ''2 They did not have ECG records of the tachycardia in all patients. The definition does not distinguish between ventricular and supraventricular tachycardia. One of my patients had P-R interval of 0.11 sec. and paroxysmal ventricular tachycardia. Careful examination revealed no other abnormalities. This patient's manifestations corresponded to the definition given of the LGL syndrome. Some authors describe a "syndrome" of short P-R interval and normal QRS complexes as the LGL syndrome.3. ~ They have forgotten the tachycardia, which is the "sine qua non" of the LGL syndrome2 They do in fact describe a part of the normal population wherein the LGL syndrome appears. Others 5 do not agree that the P-R interval is to be 0.12 sec. or less. The term "short P-R interval" seems not to be clearly defined. In recent years sexual and racial differences in the duration of the P - R interval have been noted. ~ The duration of the intervals is then of limited value without reference to race and sex.
The L G L syndrome is today interpreted as A V nodal
re-
539
Positive and negative distribution volumes To the Editor: In the February, 1975, issue of AMERICAN HEART JOURNAL, Drs. Hoffman, Rosen, and Wit discuss clinical pharmacologic considerations in the administration of antiarrhythmic agents. They state that the apparent volume of distribution is the plasma concentration divided by the dose: mg./ml. = ml. mg.
exception; the difficulty now is to obtain a normal electrocardiogram." Thus, the term applies to a rare condition with an almost continuous presence of ectopic r h y t h m frequently interrupted by brief periods of sinus rhythm. This t e r m has been used since in this connotation. The authors of the editorial "Repetitive supraventricular tachycardia in context ''2 really meant not repetitive but recurrent tachycardia. There is enough confusion in cardiac terminology already and one would hope that terms would be used in their original meaning rather than loosely.
Arthur Selzer, M.D. Division of Cardiology Presbyterian Hospital of Pacific Medical Center Buchanan and Clay Streets San ~rancisco, Calif. 94115
This would not express ml., but ml.-'. The apparent volume of distribution is actually calculated by dividing the dose by the plasma concentration1: mg. = ml. mg./ml.
William H. Jef/ery, Pharm.D. Assistant Professor of Pharmacy (Clinical) College of Pharmacy The University of New Mexico Albuquerque, N. M. 87131
REFERENCE ].
Wagner, J. G.: Biopharmaceutics and relevant pharmacokinetics, First ed., Hamilton, Ill., 1971, Drug Intelligence Publications, pp. 252-259.
REFERENCES 1. Parkinson, J., and Papp, C.: Repetitive tachycardia, Br. Heart J. 9:241, 1941. 2. Castellanos, A., Jr., and Myerburg, R. J.: Repetitive supraventricular tachycardias in context, AM. HEART J. 90:131, 1975.
Criteria for the LGL syndrome To the Editor:
Reply To the Editor: We wish to thank Dr. Jeffery for bringing to our attention this typographical error on our part. As he correctly points
out, AVD -
mg. mg,/ml.
- ml.
Brian F. Hoffman, M.D. Michael R. Rosen, M.D. Andrew L. Wit, Ph.D. Dept. of Pharmacology College of Physicians and Surgeons Columbia University 630 W. 168th St. New York, N. Y. 10032
Repetitive supraventricular tachycardia out of context To the Editor: The term "repetitive tachycardia" was coined by Parkinson and Papp I with a specific connotation and precise definition "recurrent paroxysms are the rule and normal rhythm is the
American Heart Journal
In your Editorial article for August last year (AM. HEART J. 90:131, 1975) Castellanos and Myerburg I argue for new criteria for the LGL syndrome. I do agree with them, but for different reasons: In the original article Lown, Ganong, and Levine~ describe "the syndrome of short P-R interval, normal QRS complex and paroxysmal rapid heart action. ''2 They did not have ECG records of the tachycardia in all patients. The definition does not distinguish between ventricular and supraventricular tachycardia. One of my patients had P-R interval of 0.11 sec. and paroxysmal ventricular tachycardia. Careful examination revealed no other abnormalities. This patient's manifestations corresponded to the definition given of the LGL syndrome. Some authors describe a "syndrome" of short P-R interval and normal QRS complexes as the LGL syndrome.3. ~ They have forgotten the tachycardia, which is the "sine qua non" of the LGL syndrome2 They do in fact describe a part of the normal population wherein the LGL syndrome appears. Others 5 do not agree that the P-R interval is to be 0.12 sec. or less. The term "short P-R interval" seems not to be clearly defined. In recent years sexual and racial differences in the duration of the P - R interval have been noted. ~ The duration of the intervals is then of limited value without reference to race and sex.
The L G L syndrome is today interpreted as A V nodal
re-
539
