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Programmed atrial versus programmed His bundle stimulation
Letters
On: “Of
to the Editor
jogging“
To the Editor: Dr. Burch’s recent Annotation’ indicates that the American Automobile Association reported that 8,300 joggers were killed and over 100,009 were injured in 1977 by virtue of being hit by automobiles. His reference’ is the March 22, 1978, edition of the Wall Street Journal, which indeed stated these figures on page 1, but with reference to the incidence of pedestrian deaths! The American Automobile Association has informed me that in 1977 total pedestrian injuries (ages 0 to over 65 years) were estimated to be 100,000 and pedestrian deaths were 8,700.’ The breakdown of total deaths and injuries by circumstance is shown in Table I. (Total 1977 traffic deaths, including pedestrian deaths, was 49,500).
I. Total pedestrian deaths and injuries by category Table
Crossing or entering street, or at intersection Walking Standing in roadway Pushing or working on vehicle in roadway Other labor in roadway Playing in roadway Other activities in roadway Other activities not in roadway Total
69,242 8,261 4,131 2,283 1,087 3,913 11,957 7,826 108,700
1 am certain that the incidence of joggers killed by automobile is finite, although it is not known.’ Both driver and jogger, I will allow, are too frequently reckless when in a situation of confrontation: prudence by both is in order. Dr. Burch’s conclusion that “jogging.. (is). . a serious and dangerous disease of the environment.. .“I strikes me as faulting the victim, not the perpetrator. Perhaps it is the automobile and its driver that should be considered the etiological agents of pedestrian deaths. *Note added in proof: Pedestrian deaths in the 1967-1977 period declined by 7%, the jogging boom notwithstanding (see ref. 3, page 58). Paul Miluy, Ph.D. Mt. Sinai School of Medicine New York, N. Y. 10029 REFERENCES 1. 2. 3. 4.
Burch, G. E.: Of jogging, AM. HEART J. 97:407, 1979. Burch, G. E.: Personal communication. National Safety Council: Accident Facts, 1978, pages 55 and 61. Hartung, M.: Personal communication. National Headquarters, American Automobile Association.
Long-term
prognosis
To the Editor: I read with interest the Lockwood’ on the long-term
136
of bacterial
endocarditis
paper by McNeill, Strong, and prognosis of bacterial endocardi-
tis in the April, 1978, issue of AMERICAN HEART JOURNAL. Unfortunately, there are inconsistencies between the numbers given in the table, the figure, and the text. For example: the number of patients surviving 1 year after multiple organism infection is three out of five in the table, vs. 100 per cent in Fig. 1. For cases with sterile culture the numbers are four survivors out of 16 (25 per cent) in the table, 31 per cent in Fig. 1, and the discussion gives yet another number-28 per cent. The text gives no explanation for these differences. Though the differences are slight, they give the reader a feeling of doubt as to the reliability of the results of this interesting study. M. Liron, M.D. Dept. of internal Medicine ‘%” ‘Rokach” (Hadassah) Hospital Tel-Aviv, Israel REFERENCE 1.
McNeill, Bacterial long-term
K. M., Strong, J. E., Jr., and Lockwood, W. R.: endocarditis: An analysis of factors affecting survival, AM. HEART J. 95448, 1978.
Reply To the Editor; Dr. Liron quite properly points out three discrepancies in our article (AM. HEART J. 95:448,1978). The correct figures as obtained from the original chart reviews are as follows: Sterile cultures were found in 16 patients of whom five survived a year. Multiple organisms were isolated from five patients, ail five of whom survived a year. The other numbers as given in the table and the text are errors I overlooked while proofreading the typescript following a major revision. William R. Lockwood, M.D. Associate Professor Department of Medicine School of Medicine University of Mississippi Medical Center 2500 N. State St. Jackson, Miss, 39216
Programmed atrial bundle stimulation
versus
programmed
His
To the Editor: We have read with great interest the paper entitled “Study of the temporal effects on conduction and refractoriness of the His-Purkinje system in man” by Dr. Reddy and associates in the September, 1978, issue of the JOURNAL.' This paper clearly demonstrated temporal stability of refractoriness in the HisPurkinje system. Results of the study provide baseline data for future investigations of antiarrhythmic drugs acting on the distal part of the A-V conduction system. However, in over 90 per cent of the cases investigated programmed atria1 stimulation proved to be ineffective in assessing refractoriness of the His-Purkinje system because of A-V nodal refractoriness. Theoretically, programmed His bundle stimulation seems
July, 1979, Vol. 98, No. 1
Letters
to the Editor
Fig. 1. The left ancE right panels show atria1 and His bundle extrastimulation with paper speeds of 100 and 50 mm./sec., respectively. Top, Extrastimuli with normal QRS complexes. Middle, The longest H,-H, and V,-S intervals associated with incomplete right bundle branch block [relative refractory period with aberration). Bottom, The longest H,-H, and V,-S intervals associated with complete right bundle branch block, HZ-V, and S-V, prolongation (relative refractory period with H-V prolongation).
to be the ideal approach to delineate electrophysiological properties of the His-Purkinje system. As was demonstrated in animal experiments from the same laboratory,? our preliminary results in man also indicate that programmed His bundle stimulation is the most useful method in measuring refractoriness of the His-Purkinje system.3 We have found this method to be successful in the majority of cases in patients with intraventricular conduction disturbance. An illustrative example for validation of this technique in evaluation of the His-Purkinje system is presented in Fig. 1 by comparing responses obtained during programmed atria1 and His bundle stimulation. In the future, programmed His bundle stimulation will probably allow more thorough categorization of the intraventricular conduction disturbances and a more accurate assessment of drug effects on the His-Purkinje system. L&s&5 Littmann, M.D. J&sef Tenczer, M.D. 3rd Department of Medicine Semmelweis University of Medicine Eiitviis utca 12 H-1121 Budapest Hungary REFERENCES 1.
Reddy, C. P., Damato, A. N., Akhtar, M., Dhatt, M. S., Gomes, J. A., and Foster, J. R.: Study of the temporal effects on conduction and refractoriness of the HisPurkinje system in man, AM. HEART J. 96:316, 1978.
American
Heart
Journal
2.
3.
Gomes, J. A. C., Damato, A. N., Bobb, G. A., and Lau, S. H.: The effect of digitalis on refractoriness of the intact canine His-Purkinje system, Circulation 55284, 1978. Tenczer, J., Littmann, L., Molnar, F., and Kekes, E.: Electrophysiological studies in infra-His conduction defects, Fifth International Congress on Electrocardiology, Abstracts 130-5, 1978.
Reply To the Editor: We thank Drs. Littmann and Tenczer for their comments concerning our recent publication.’ We agree that in the majority of patients the determination of refractoriness of the His-Purkinje system (HPS) by the atria1 extrastimulus method is limited by the A-V nodal refractoriness’ and programmed His bundle (HB) stimulation may be an ideal method for measuring the refractoriness of HPS.? However, several theoretical and practical consideration may make this technique less valuable in clinical situations: (1) stable HB pacing may be difficult to achieve in all patients because of anatomical variations and catheter movement caused by cardiac and respiratory movements3; (2) the electrode catheter used for pacing the HB may pace several structures in the vicinity of HB-i.e., HB, right bundle, ventricular muscle, resulting in variable QRS patterns and changing stimulus to ventricular activation (S-V) intervals’; (3) S-V interval may ala0 vary depending upon the region of the HB paced”; (4) the higher stimulus strength required to pace the HB may affect the
137
On: “Of
to the Editor
jogging“
To the Editor: Dr. Burch’s recent Annotation’ indicates that the American Automobile Association reported that 8,300 joggers were killed and over 100,009 were injured in 1977 by virtue of being hit by automobiles. His reference’ is the March 22, 1978, edition of the Wall Street Journal, which indeed stated these figures on page 1, but with reference to the incidence of pedestrian deaths! The American Automobile Association has informed me that in 1977 total pedestrian injuries (ages 0 to over 65 years) were estimated to be 100,000 and pedestrian deaths were 8,700.’ The breakdown of total deaths and injuries by circumstance is shown in Table I. (Total 1977 traffic deaths, including pedestrian deaths, was 49,500).
I. Total pedestrian deaths and injuries by category Table
Crossing or entering street, or at intersection Walking Standing in roadway Pushing or working on vehicle in roadway Other labor in roadway Playing in roadway Other activities in roadway Other activities not in roadway Total
69,242 8,261 4,131 2,283 1,087 3,913 11,957 7,826 108,700
1 am certain that the incidence of joggers killed by automobile is finite, although it is not known.’ Both driver and jogger, I will allow, are too frequently reckless when in a situation of confrontation: prudence by both is in order. Dr. Burch’s conclusion that “jogging.. (is). . a serious and dangerous disease of the environment.. .“I strikes me as faulting the victim, not the perpetrator. Perhaps it is the automobile and its driver that should be considered the etiological agents of pedestrian deaths. *Note added in proof: Pedestrian deaths in the 1967-1977 period declined by 7%, the jogging boom notwithstanding (see ref. 3, page 58). Paul Miluy, Ph.D. Mt. Sinai School of Medicine New York, N. Y. 10029 REFERENCES 1. 2. 3. 4.
Burch, G. E.: Of jogging, AM. HEART J. 97:407, 1979. Burch, G. E.: Personal communication. National Safety Council: Accident Facts, 1978, pages 55 and 61. Hartung, M.: Personal communication. National Headquarters, American Automobile Association.
Long-term
prognosis
To the Editor: I read with interest the Lockwood’ on the long-term
136
of bacterial
endocarditis
paper by McNeill, Strong, and prognosis of bacterial endocardi-
tis in the April, 1978, issue of AMERICAN HEART JOURNAL. Unfortunately, there are inconsistencies between the numbers given in the table, the figure, and the text. For example: the number of patients surviving 1 year after multiple organism infection is three out of five in the table, vs. 100 per cent in Fig. 1. For cases with sterile culture the numbers are four survivors out of 16 (25 per cent) in the table, 31 per cent in Fig. 1, and the discussion gives yet another number-28 per cent. The text gives no explanation for these differences. Though the differences are slight, they give the reader a feeling of doubt as to the reliability of the results of this interesting study. M. Liron, M.D. Dept. of internal Medicine ‘%” ‘Rokach” (Hadassah) Hospital Tel-Aviv, Israel REFERENCE 1.
McNeill, Bacterial long-term
K. M., Strong, J. E., Jr., and Lockwood, W. R.: endocarditis: An analysis of factors affecting survival, AM. HEART J. 95448, 1978.
Reply To the Editor; Dr. Liron quite properly points out three discrepancies in our article (AM. HEART J. 95:448,1978). The correct figures as obtained from the original chart reviews are as follows: Sterile cultures were found in 16 patients of whom five survived a year. Multiple organisms were isolated from five patients, ail five of whom survived a year. The other numbers as given in the table and the text are errors I overlooked while proofreading the typescript following a major revision. William R. Lockwood, M.D. Associate Professor Department of Medicine School of Medicine University of Mississippi Medical Center 2500 N. State St. Jackson, Miss, 39216
Programmed atrial bundle stimulation
versus
programmed
His
To the Editor: We have read with great interest the paper entitled “Study of the temporal effects on conduction and refractoriness of the His-Purkinje system in man” by Dr. Reddy and associates in the September, 1978, issue of the JOURNAL.' This paper clearly demonstrated temporal stability of refractoriness in the HisPurkinje system. Results of the study provide baseline data for future investigations of antiarrhythmic drugs acting on the distal part of the A-V conduction system. However, in over 90 per cent of the cases investigated programmed atria1 stimulation proved to be ineffective in assessing refractoriness of the His-Purkinje system because of A-V nodal refractoriness. Theoretically, programmed His bundle stimulation seems
July, 1979, Vol. 98, No. 1
Letters
to the Editor
Fig. 1. The left ancE right panels show atria1 and His bundle extrastimulation with paper speeds of 100 and 50 mm./sec., respectively. Top, Extrastimuli with normal QRS complexes. Middle, The longest H,-H, and V,-S intervals associated with incomplete right bundle branch block [relative refractory period with aberration). Bottom, The longest H,-H, and V,-S intervals associated with complete right bundle branch block, HZ-V, and S-V, prolongation (relative refractory period with H-V prolongation).
to be the ideal approach to delineate electrophysiological properties of the His-Purkinje system. As was demonstrated in animal experiments from the same laboratory,? our preliminary results in man also indicate that programmed His bundle stimulation is the most useful method in measuring refractoriness of the His-Purkinje system.3 We have found this method to be successful in the majority of cases in patients with intraventricular conduction disturbance. An illustrative example for validation of this technique in evaluation of the His-Purkinje system is presented in Fig. 1 by comparing responses obtained during programmed atria1 and His bundle stimulation. In the future, programmed His bundle stimulation will probably allow more thorough categorization of the intraventricular conduction disturbances and a more accurate assessment of drug effects on the His-Purkinje system. L&s&5 Littmann, M.D. J&sef Tenczer, M.D. 3rd Department of Medicine Semmelweis University of Medicine Eiitviis utca 12 H-1121 Budapest Hungary REFERENCES 1.
Reddy, C. P., Damato, A. N., Akhtar, M., Dhatt, M. S., Gomes, J. A., and Foster, J. R.: Study of the temporal effects on conduction and refractoriness of the HisPurkinje system in man, AM. HEART J. 96:316, 1978.
American
Heart
Journal
2.
3.
Gomes, J. A. C., Damato, A. N., Bobb, G. A., and Lau, S. H.: The effect of digitalis on refractoriness of the intact canine His-Purkinje system, Circulation 55284, 1978. Tenczer, J., Littmann, L., Molnar, F., and Kekes, E.: Electrophysiological studies in infra-His conduction defects, Fifth International Congress on Electrocardiology, Abstracts 130-5, 1978.
Reply To the Editor: We thank Drs. Littmann and Tenczer for their comments concerning our recent publication.’ We agree that in the majority of patients the determination of refractoriness of the His-Purkinje system (HPS) by the atria1 extrastimulus method is limited by the A-V nodal refractoriness’ and programmed His bundle (HB) stimulation may be an ideal method for measuring the refractoriness of HPS.? However, several theoretical and practical consideration may make this technique less valuable in clinical situations: (1) stable HB pacing may be difficult to achieve in all patients because of anatomical variations and catheter movement caused by cardiac and respiratory movements3; (2) the electrode catheter used for pacing the HB may pace several structures in the vicinity of HB-i.e., HB, right bundle, ventricular muscle, resulting in variable QRS patterns and changing stimulus to ventricular activation (S-V) intervals’; (3) S-V interval may ala0 vary depending upon the region of the HB paced”; (4) the higher stimulus strength required to pace the HB may affect the
137