Vasomedical

(VASO)

reported its second-quarter earnings this afternoon, attracting 1.4 million shares of interest before the bell rang. It rose 7/32 to 1 9/16 during the day session, which is a 16.7% gain in the minuscule world of penny plays. Tonight, the company continued to trade heavily and post gains. It was last up 3/32 to 1 21/32 on 1.6 million shares on

Island

ECN, easily the most-active issue.

So, Vasomedical, huh?

Yup. The medical-device maker is based in Westbury, N.Y., and is actively engaged in bringing its enhanced external counterpulsation system, or EECP, into the marketplace. These EECPs are designed to treat patients with coronary artery disease without using invasive surgery, thereby minimizing trauma to the delicate heart muscles. The technology behind the system is deceptively simple. It uses pressurized cuffs to squeeze veins and arteries in the legs to help circulate blood and then deflates these same cuffs when the heart pumps, reducing the load on the heart. A computer organizes the entire system to syncopate with a patient's heartbeat.

Today Vasomedical announced that its second-quarter revenue from the sale and lease of these EECPs was $3 million, more than 700% better than last year's $364,000. Per-share earnings were nil in the same period, beating last year's 4-cent loss.

The company said the reason for the increase in revenue and earnings was due to a decision by the

Health Care Financing Administration

, the government agency controlling

Medicare

, to cover the use of EECPs nationwide.

At the second-most-active spot,

PRT Group

(PRTG)

was another mighty-mite whose big day turned into a big night. After gaining 7/8 to 3 3/16 on 1.2 million shares during the day session, it was last up 2 1/16 to 5 1/4 on 750,000 shares on Island.

Last night, PRT Group gave an update regarding its ten-month partnership with

Sun Microsystems'

(SUNW) - Get Report

Sun-Netscape Alliance

. In a press release, the company announced that it developed an efficient model for integrating e-business software with clients' pre-existing network. PRT Group said that it has successfully implemented these e-tailing solutions, in conjunction with the Sun partnership, in ten different projects for a variety of different clients, from a major Internet carrier to an international petroleum company.

Major tech names were nowhere to be found on Island's most-actives list, with penny stocks establishing dominance heading into the long

Martin Luther King

holiday weekend.

Name stocks that traded did so lightly.

Yahoo!

(YHOO)

extended today's gain of 6 5/16 into the later session with a gain of 3 1/16 to 356 on 48,000 shares.

Qualcomm

(QCOM) - Get Report

rose 1 17/32 to 141 31/32 on 38,000 shares.

CMGI

(CMGI)

rose 9/16 to 122 1/2 on 32,000 shares.

Island ECN, owned by Datek Online, offers trading, mainly in Nasdaq-listed stocks, from 8 a.m. to 8 p.m. EST.

.

Confused?

TheStreet.com

explains how the rules change when the sun goes down in Investing Basics: Night Owl, a section devoted to after-hours trading.