throughout cardiopulmonary bypass when bubble oxy- eliminate or significantly decreasethe number of oxygengenators were used, thus confirming the findings ob- ator-generated microbubbles reaching the arterial circutained with microbubble activity monitors.’ Moreover, lation. even though a specific search was not performed, the number of microemboli seemeddirectly related to the pump flow. Conversely, when hollow-fiber oxygenators 1. PearsonDT. Microemboli: gaseousand particulate. In: Taylor KM, ed.Cardiopulmonary Bypass. London: Chapman and Hall, 1986:313-353. were used, microbubbles were only visualized within the 2. Barash PG. Cardiopulmonary bypassand postoperativeneurologic dysfuncfirst few minutes of cardiopulmonary bypass after the tion. Am Heart J 1980,99:675-677. infusion of the priming solution. It remains to be verified 3. Kirklin JW, Barratt-Boyes BG. Cardiac Surgery. New York: Wiley Medical, whether other types of membrane oxygenators may be 4.198658. Mitchell MM, SutherlandGR, GussenhovenEJ, TaamsMA, RoelandtJRTC. even more effective in eliminating microbubbles. Transesophagealechocardiography.J Am Sot Echo 1988;1:362-377. In view of our findings, an arterial filter should be 5. Seward JB, Khandheiria BK, Oh JK, Abel MD, HughesRW, EdwardsWD, BA, Freeman WK. Tajik AJ. Tramesophageal echocardiography: techincorporated into the cardiopulmonary bypasscircuit, es- Nichols nique, anatomic correlations. implementation and clinical applications. Mayo pecially when bubble oxygenators are used. This would Clin Proc 1988,63:649-680.

Unsolicited Howard R. Horn,

Medical

Journals

MD

he proliferation of medical mailings has skyrocketed in recent years and now approaches overwhelming T proportions fo; busy American cardiologists. The majority -of such “litera&re” is unsolicited and much of it appears to be published for mostly financial considerations. While all physicians receivea number of unsolicited medical journals in the mail, it is my impression that cardiologists lead the pack in the number received. To obtain a realistic assessmentof this number, a count was made of all medical publications received in the mail during a single month in 1989.The titles of thesejournals and mailings with dates received are listed in Table I. As seenin this Table, both the total number of mailings and thosereceivedon a single day are astounding! A cardiologist receiving 9 journals on 1 day is probably receiving more than many physicians in other specialities receivein a week or even a month. Even more astounding is the observation that of 108 total pieces of medical mail received during 1 month, 88% was unsolicited. An interesting paradox is provided by the aforementioned numbers. Cardiologists, probably the busiest specialists in our society, now appear to be the ones also bearing the brunt of the proliferation of unsolicited medical literature. The conscientious cardiologist striving to keepup with the literature may feel compelled to read or scantheseunsolicited items, creating further demandson already limited time. To deal with this unwieldy task, somecardiologists may have to developnovel approaches. One approach that I have periodically adopted entails keeping journals in the back seat of the car so they are conveniently available to scan and then discard anytime, anywhere! Finally, most of the articles in the unsolicited journals are written by physicians and some are published by publishers seekingprofit only. It might be wiser for physiFrom the Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee, Memphis, The Health Science Center, 951 Court Avenue, Room 348 D, Memphis, Tennessee 38 163. Manu-

script received and acceptedApril 16, 1990.

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ciansto spendtheir writing energieson peer-reviewpublications that end up on library shelvesrather than on throwaways that end up in trashcans. TABLE I Medical Journals and Mailings Received on a Daily Basis From May 15,1989 to June 15,1989 May 15 Drug Therapy Consultant Emergency Medicine Human Sexuality Hospital Practice American Medical News May 16 Clinical Symposia Medical Tribune New England Journal of Medicine American Journal of Cardiology Clinical Cardiology M.D. Magazine Cardiology Product News Cortlandt Forum Choices in Cardiology May 17 Cardiology CV Reviews & Reports May 18 Cad Ca Journal for Clinicians May 19 Physicians & Computers Primary Cardiology May 20 Physicians’ Travel & Meeting Guide Monthly Prescribing Reference May 22 Physicians’ Financial News CARD10 Physicians’ Lifestyle Magazine May 23 Cardiology

Annals of Internal Medicine ACC Convention Reporter C-V News AHA Focus SeriesHypertension Side Streets Medical Tribune Post-Graduate Medicine Internal Medicine World Report May 24 Acute Care Therapeutics/ ACT American Medical News Myocardial infarctionRationale for Rx-Highlights of University of Florida Conference Mayo Clinic Proceedings Internal Medicine for the Specialist May 25 Cleveland Clinic Journal of Medicine Geriatric Medicine Today New England Journal of Medicine National CV Bulletin May 26 Emergency Medicine Memphis Health Care News Internal Medicine News Report of Chatham MeetingCHF/New Approaches to Rx Hospital Practice CV Rounds May 27 Medical Electronics

TABLE I (continued) VARIA PRN-Frontlrne Report June 3 Medical Tribune June 5 Cardiology World News The Physrcian & Sports Medicine Cardiology Medical News June 6 American College of Physicians Observer Journal of the American College of Cardiology American Journal of Cardiology Symposrum June 7 Monthly Prescribing Reference Omni Medical Contemporary Internal Medicine New England Journal of

Equipment News American Journal of Cardiology May 29 and 30 New England Journal of Medicine Journal of Cardiac Rehabilitation Medrcal World News Today in Medicine Physicians Financial News June 1 American Medrcal News Senior Patient News-From the CV Center of Emory University Your Patient & Fitness in Cardiology Mg+ Alert Line June 2 Internal Medicine News New Bulletrn-ACC 38th Annual Session Total peces of medical mall in 1 month % medical mai unsoluted = 88

Effect of Altered Byron F. Vandenberg,

Medrcine June 9 Human Sexuality Drversion Arrhythmra Clinic Councrl for Tobacco Research Clrnrcal Cardrology Memphrs Health Care News The Journal of Myocardial lschemta June 10 Private Practice American College of Cardiology-Annual Scientific Sessron News LeBonheur News Hospital Medrcine The Journal of Clinical Illness June 12and 13 Physrcrans Frnancral News New England Journal of Medicrne

Medrcrne World News Amerrcan Heart Journal Annals of Internal Medicine Drrectory for the 90’s Medical Trrbune Emergency Medicine Archives of Internal Medrcine Practrcal Cardiology Practrcal Cardrology Journal of the National Medtcal Assocratron June 14 Preventrve Cardiology ‘89 Physicians Management Modern Medicine Internal Medicine World Report June 15 Physrcrans Market Place ACC Cardrology New Horizons for the Physicran-M.D. Hosprtal Practrce

= 108

Flow on Mitral MD,

Valve Anulus

and Richard E. Kerber,

troke volume and cardiac output are accurately estimated by Doppler echocardiographic methods that S rely on inflow velocities and orifice area of the mitral valve.‘s2Changesin inflow velocities representchangesin flow, but this requires the assumption of a stable mitral anulus area. It is known that the anulus area decreasesby an estimated 20 to 50% during systole,3*4but there are few data on the effect of altered filling on the anulus. This study determinesthe effectsof flow increasedwith dobutamine or decreasedwith phenylephrine on the mitral anulus.

in Dogs

MD

8 ultrasonoscope. With the dogs laying on their right sides, the parasternal long-axis view was obtained with a 5 mHz transducer. The animals were then turned onto their left sides and mitral inflow velocities were recorded using Doppler echocardiography. Positioning dogs on their left sides permitted optimal visualization of a 4chamber apical view. The Doppler ultrasound beam was

We studied the effects of altered flow on the mitral anulus in 10 dogs that were part of another study. The dogs were anesthetized with sodium thiopental30 mg/kg intravenously, intubated and ventilated. Catheters were inserted in the femoral arteries for monitoring blood pressure and in the veins for administering fluids and medications. The dogs were allowed to recover for at least 72 hours. Before echocardiographic study, they were sedated with 0.2 to 0.4 ml of Innovar-Vet (fentanyl citrate and droperidol, Taylor Pharmaceutical Co.) intravenously. Two-dimensional echocardiography was performed with an Advanced Technology Laboratories Ultramark From the Cardiovascular Center, Department of Internal Medicine, [Jniversity of Iowa College of Medicine, Iowa City, Iowa 52242. This study was supported in part by a grant-in-aid (Dr. Vandenberg) from the Iowa Affiliate of the American Heart Association, Des Moines, Iowa. Manuscript received November 27, 1989; revised manuscript received April 9, 1990, and accepted April IO.

FIGURE 1. Parastemai bng-axis view of left venbide. Arrows indicate insertion points of mitral bffets.

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