* Sees Q2 revenue $3.1-$3.3 mln

* Withdraws outlook for system placements for 2009

* Shares fall 32 pct in after-market trade (Adds analyst's comments, updates stock move)

By Anand Basu

BANGALORE, July 6 (Reuters) - Hansen Medical Inc (HNSN.O: Quote, Profile, Research) reported preliminary second-quarter revenue that fell short of analysts' expectations, citing delay in purchase decisions by customers, sending its shares tumbling 32 percent after market.

"Sensei system sales during the second quarter were adversely affected by general macroeconomic conditions that continue to significantly impact our potential customers' capital spending," Chief Executive Frederic Moll said in a statement.

Several potential customers sought additional approvals prior to making their purchase decision or spent time evaluating alternative financing arrangements, resulting in orders moving out of the quarter, Moll added.

Hansen's Sensei robotic catheter system helps to place mapping catheters within the heart easily, during complex cardiac arrhythmia procedures.

"I was expecting the company to come in weak, I just didn't know to what degree," Needham & Co analyst Sameer Harish said by phone.